Fix segmentation fault if extensions dont provide information file
Create caja.appdata.xml

An appdata file for inclusion in the upcoming software centers as per the new freedesktop.org specs.

It should be placed in /usr/share/appdata/ similar to the way .desktop files are placed in /usr/share/applications/, e.g. if you have a "$(datadir)/applications" definition in your makefiles, you need to add a "$(datadir)/appdata" as well.

Please, skim through the file in case I made a mistake and please, include it in the 1.8 branch as well.

Thanks!
appdata: Add autotool bits for appdata
Sync translations with transifex
Bump version to 1.9.3
appdata: Add necessary markers for translation
Sync translations with transifex
Sync translations with transifex
Merge remote-tracking branch 'upstream/master'