dock:: support 2 kind of app action.

there 2 kind of app action so far:
1. .* Shortcut Group, like google chrome.
2. Desktop Action .*, like firefox.

glib just supports the second one.

NOTE:
because we cannot pass NULL to glib.KeyFile.GetLocaleString like C, so the
locale must be passed expclitly. Making a little port from glib.

Change-Id: I8da6b41e0f08167e8d5ffd345d74e19627857728