* define vars to hold scratch dir path & max age of files
 * use templates instead of static files for config & script
 * retain existing user scratch dir unless not owned by user
Ignore backup files in repo

	new file:   .gitignore
	modified:   README.md
	modified:   defaults/main.yml
	deleted:    files/local_scratch.conf
	deleted:    files/scratch_setup.sh
	modified:   tasks/main.yml
	new file:   templates/local_scratch.conf.j2
	new file:   templates/scratch_setup.sh.j2