Merge branch 'master' into tmp

Conflicts:
	libmate-desktop/mate-desktop-utils.c
Merge branch 'tmp' of github.com:dnk/mate-desktop into tmp
Merge branch 'master' into tmp
Merge branch 'tmp' into dev
Merge branch 'dev' of github.com:dnk/mate-desktop into dev
gtk3: mate_bg_create*thumbnail should return GdkPixbuf*

this functions are used at mate-control-center
Merge branch 'dev' of github.com:dnk/mate-desktop into dev
Sync translations with transifex
Bump version to 1.8.0
Merge pull request #102 from dnk/rgba

gtk3: GdkRGBA support
Revert "gtk3: mate_bg_create*thumbnail should return GdkPixbuf*"

This reverts commit 0eef05307bd0c2acb5c780b8f85a239ca810625d.
Revert "gtk3: GdkRGBA support"

This reverts commit e95d24559060365eb4fee8154ad82434bf3c8a0a.
Remove desktop-docs folder

Closes https://github.com/mate-desktop/mate-desktop/issues/103
Bump version to 1.9.0
Update NEWS
Remove user guide

We are preparing https://github.com/mate-desktop/mate-user-guide now
Update POTFILES.in
mate-about: MATE is the continuation of GNOME 2
mate-dconf: Add void where needed
Add more GSettings common functions