Pull Action

Introducing the pull action requiring lftp. How it works:
- Fetch:
 - Checkout the commit that was deployed to the server
 - Mirror files of the server
 - Commit all changes (this is the server state)
 - Upload the new SHA1 of the server state
- Merge:
 - Checkout your branch/commit again
 - Merge the remote changes
Merge remote-tracking branch 'git-ftp/pull' into develop

Conflicts:
	git-ftp
	tests/git-ftp-test.sh