Remove virtual buttons doc, save touchscreen calibration guide

The virtual button infrastructure no longer seems to be a part of Apertis.
The screen calibration description still seems valid, so move this to its
own page under `guides/`.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

content/docs/virtual_buttons.md

-+++
-date = "2014-12-17"
-weight = 100
-
-title = "Virtual Buttons"
-
-aliases = [
-    "/old-wiki/Docs/Virtual_Buttons"
-]
-+++
-
-## Virtual Buttons Daemon
-
-To allow using off-screen touch sensor areas as virtual buttons, a
-virtual button daemon has been provided.
-
-The virtual button daemon (/usr/bin/buttonsd) requires a configuration
-file in the following format:
-
-    device "VIRTUAL KEYBOARD" 0xf00:1234 from "/dev/input/by-id/usb-QUANTA_OpticalTouchScreen-event-if00" {
-            button 1700,0 220x540 KEY_J repeats
-            button 1700,540 220x540 KEY_Q
-    }
-
-The fields after device are the following:
-
-"NAME" for the name the virtual device will present itself as. this is
-the name that will appear in xinput's list, and the name that must be
-used if the device is to be statically configured in xorg.conf
-
-The \#\#\#\#:\#\#\#\# is a vendor id followed by a product id, the two
-numbers may be given in hexadecimal or decimal.
-
-The string after the word from is the pathname of the real device node
-on the filesystem. In the example, the touch sensor for the Iiyama
-multi-touch monitor is used.
-
-On an mx6 sabrelite with an egalax touch panel,
-"/dev/input/by-path/platform-21a8000.i2c-event" would be appropriate.
-This string must be enclosed in quotes.
-
-Inside the {} are a list of button definitions. the format is:
-
-    button X,Y WxH keycode [repeats]
-
-x, y, w, h specify the x and y co-ordinates from the touch pad for the
-corner of the button, and wxh specifies the width and height. keycodes
-come from /usr/include/input.h KEY_A, KEY_B, ... correspond to regular
-keyboard keys, but there are many other keys listed in the file that
-might be interesting (such as KEY_HOME, KEY_AUDIO)
-
-The word "repeats" is optional. If present, the key will continue to
-repeat for as long as it is held, like holding down a key on the
-keyboard. If it's not present then pressing the area on the touch screen
-will immediately generate both a key press and key release event, and
-holding down the virtual key will do nothing.
-
-The button daemon must be started as root in order to have access to
-input devices. It takes a single command line parameter — the name of
-the configuration file.
-
-    sudo buttonsd conffile
-
-## Evdev Calibration
-
-By default, X will scale the touchscreen's input to the display. Off
-screen areas will be included in this, and if buttonsd is running,
-generate both the usual touch events and the new button events.
-
-To remove off screen areas, evdev calibration must be used. When
-calibration is used, touchscreen co-ordinates outside of the calibrated
-area will act as if they're off screen. moving a finger from inside the
-area to outside the area will result in a release event at the edge of
-the screen. Moving from outside to inside will result in a press. The
-intent is that the screen behave as if the calibrated area was its
-physical boundary.
-
-Setting this up for the eGalax touch screen on sabrelite can be done by
-creating a file in /usr/share/X11/xorg.conf.d with the contents:
-
-    Section "InputClass"
-            Identifier "Calibrated Touch Screen"
-            MatchProduct "eGalax Touch Screen"
-            Driver "evdev"
-            Option "Calibration" "0 16384 0 32768"
-    EndSection
-
-or, for the Iiyama touch screen on the intel reference platform:
-
-    Section "InputClass"
-            Identifier "Calibrated Touch Screen"
-            MatchProduct "QUANTA OpticalTouchScreen"
-            Driver "evdev"
-            Option "Calibration" "0 1000 0 1080"
-    EndSection
-
-The calibration numbers are low X, high X, low Y, high Y in unscaled
-touch sensor co-ordinates. X will scale touch sensor motion inside this
-range to fill the display.
-
-This can also be done at run-time without changing configuration files
-by doing the following: (xinput may need to be installed with "apt-get
-install xinput")
-
-    xinput "eGalax Touch Screen" "Evdev Axis Calibration" 0 16384 0 32768
-
-If using different devices, use
-
-    xinput list
-
-to find the name.

content/guides/touchscreencalibration.md

++++
+date = "2014-12-17"
+weight = 100
+
+title = "Touchscreen Calibration"
++++
+
+By default, X will scale the touchscreen's input to the display, this typically
+results in off screen areas will be included, resulting in touch sensing to be
+
+To remove off screen areas, evdev calibration must be used. When calibration is
+used, touchscreen co-ordinates outside of the calibrated area will act as if
+they're off screen. moving a finger from inside the area to outside the area
+will result in a release event at the edge of the screen. Moving from outside
+to inside will result in a press. The intent is that the screen behave as if
+the calibrated area was its physical boundary.
+
+Setting this up for the eGalax touch screen on SABRE Lite can be done by
+creating a file in `/usr/share/X11/xorg.conf.d` with the contents:
+
+    Section "InputClass"
+            Identifier "Calibrated Touch Screen"
+            MatchProduct "eGalax Touch Screen"
+            Driver "evdev"
+            Option "Calibration" "0 16384 0 32768"
+    EndSection
+
+or, for the Iiyama touch screen on the intel reference platform:
+
+    Section "InputClass"
+            Identifier "Calibrated Touch Screen"
+            MatchProduct "QUANTA OpticalTouchScreen"
+            Driver "evdev"
+            Option "Calibration" "0 1000 0 1080"
+    EndSection
+
+The calibration numbers are low X, high X, low Y, high Y in unscaled touch
+sensor co-ordinates. X will scale touch sensor motion inside this range to fill
+the display.
+
+This can also be done at run-time without changing configuration files by doing
+the following (xinput may need to be installed with `apt-get install xinput`):
+
+    xinput "eGalax Touch Screen" "Evdev Axis Calibration" 0 16384 0 32768
+
+If using different devices, use
+
+    xinput list
+
+to find the name.