clean untracked files in the working directory

EXAMPLES
	git clean
		remove all untracked files that are not .gitignored
	git clean -n
		do a dryrun, simply printing what would be deleted
	git clean -d
		also remove all directories that become empty due to cleaning
	git clean -f
		force clean
	git clean -i
		interactive removal, asking for permission for each file
	git clean -x
		also remove all .gitignored files

FLAGS
	-n	dryrun
	-i	interactive
	-d	delete empty directories as well
	-f	force clean
	-x	also delete .gitignored files
