v0.9.1

Correct some copyright header merchantability statement to point to the project GPL license

Stable release

Forked at v44 from gnome-session, budgie-session has undergone extensive refactoring to ensure install artefacts do not clash from those produced by gnome-session.

For this initial release, all of the systemd targetshave been removed. budgie-session retains the --builtin argument to enable budgie-desktop v10.x to correctly launch.