Add an example spec file
Add some error prefixes to the desktop plugin
Alpm support
	- autotools configuration.
	- alpm functions implementation in progress.
Update of alpm backend:
	- Changed copyright to myself in license header.
	- Fixed compilation warning.
	- Partial implementation of cra_package_alpm_ensure_simple.
Alpm packages handling. Still work in progress.
Work in progress.
Fixed memory errors and removed unused debug.
Fixed paths in filelist.