upstream changelog missing on Ubuntu packages
Merge pull request #36 from darealshinji/patch-1

upstream changelog missing on Ubuntu packages
Installer: delete MKVToolNix GUI preview link on the desktop
install wxgtk 3.0 and fallback to wxgtk 2.8 if it doesn't exist
Merge remote-tracking branch 'refs/remotes/darealshinji/patch-1'
Debian/Ubuntu build files: shorten dependency list
Translations: update Spanish
common: re-write get_environment_variable() without fixed buffer size
common: implement get_environment_variable() for non-Windows
GUI: don't display the preview warning if NO_WARNING is set to 1
GUI: automatically set the title from added source files
GUI: implement automatically setting the output file name
GUI: use .isEmpty() for stating intentions clearly
GUI: use .clear() for clearing lists

.empty() is just a compatibility function for stdlib and doesn't clear
the list. It's the equivalent of .isEmpty().

This fixes clearing the lists when loading/resetting configs.
ChangeLog update
installer: no GUI shortcut on desktop if the user doesn't want them
GUI: implement storing the job queue on exit
GUI: implement retrieving the job queue on startup
GUI: don't increment running index twice during job loading
GUI: don't write/read job's internal IDs