Allow a config file to predefine variables and skip prompts.
fix spacing on usage
Add example config file for documentation.

Signed-off-by: Michael McCracken <mike.mccracken@canonical.com>
Fix OPTS string - re-add colon after opt_configfile
merge with origin/master
update usage comment again
add HELP back to usage shortopt list
move example to separate file
install example file
merge and correct usage message
Merge pull request #19 from mikemccracken/add-config-file

Add config file support