Some more work on actions:

- Add first selected file display name token
- Add parent display name token
- Unify string expansion across exec, label, tooltip
- Add separator definition for exec file list
- Add quote type for exec file list (single, double, backtick)
Update sample action, gedit lang files
Add optional Dependencies key to actions - action will not run without these
programs in the search path.
Add mailto actions, add 'nodirs' option for action extensions.
Remove hardcoded mailto menu options (use the actions instead)
Fix logging mistake
Some fixes - grab the parent dir information if we're expecting
a file name but none is given, and some special handling for the
Desktop folder
Move action visibility calc function to nemo-action.c, where it belongs.
Change new launcher to actions api
add new launcher action
Tweak action a bit
Re-add mnemonic key for add launcher action
Add scripts to generate i18n string file for makepot, and a script
to merge translated strings into .nemo_action files.

The action files should start in ./data/*.nemo_action.in  and will
be eventually copied to files with the merge script
Fix makepot, extract script
Remove array length properties from nemo actions, just use g_strv_length.
Make selection string case insensitive like everything else.
Fix setter/getters
Fix null pointer array
Use system translations instead of package mo files (since we'll be using
cinnamon-translations package now)
Add conditions for actions - desktop, gsettings key, removable, dbus listener