Add Localizations to the weather app

Use application's locale to load the relevant translation if available.

Automate the run of lrelease to generate the translation files *.qm
for each language available. Embed the *qm files in the application.

Add ts-<lang> and commit-ts targets for convenience while dealing with
translations files.

Change-Id: I9ff96fb8468a04f4657e425c2c9c730cbcc4481f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>