added lib/editify_helpers
updated editify.sh to have better errors, warnings
note that return <negative> doesn't work (in Ubuntu?), only positive #

Usage: editify <--help|--list|--push|--pop|--reset|<gem name> [gem location]>
--help shows this message
--list any editified gems in project
--push any editified gems by removing symlinks and keeping gem names
--pop any editified gems by restoring symlinks using any updated SHAs
--reset any editified gems by removing symlinks and forgetting gem names
<gem name> toggles edifitication on/off for the gem in the bundler cache
  location using either a relative source directory or the directory given.now supports:
--list
avoid leaking shell-local variables
Merge pull request #1 from xeger/editify_helper

added lib/editify_helpers