Remove user pages

Most of the user pages contain links to pages written by the user as some
users took the convention of writing pages in their user areas before
moving into a more suitable location once they had been reviewed. As this
is no longer the expected workflow and the new site does not have the
concept of users, remove these pages.

Any pages with potential value as still in progress have been moved to
branches which can be reviewed an merged properly in the future.

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