Blender Git Loki

Fix (IRC reported) bad handling of Text data-block user count.

Reported on IRC by dfelinto, thanks.

Root of the issue was that opening a new text file would create
datablock with one user, when Text editor is actually a 'user one' user.

This was leaving Text datablocks in inconsitent user count, and
generating asserts in BKE_library area.

Also changed a weird piece of code related to that extra user thing in
main remapping func.