possibility to ignore some updates in pamac-updater, do not close progress window when yaourt failed and other improvements

- complete rewrite in vala
- it now directly depends on libalpm so it is easier to maintain
- it is faster and uses less memory
- alpm bindings for vala, other people could be interested
- a DBus daemon which can perform every tasks which need root access using polkit to check authorization, it can be used by any other program.
- pamac-manager and pamac-updater as you know before but with some new design, try them !
- the progress dialog now includes a terminal, it permits to launch yaourt which is used now to build packages from AUR.
- reinstall a package
- install optional dependencies of a package
- mark a package as explicitly installed