added ability to set a different JS file for snapping images - Non JS usage
updated docs for snap usage
set snap.js as default incase using older config
changed config back to snap.js
updated readme
Merge pull request #46 from BBC-News/different_snap_file

Added config option to set snapping file
Merge branch 'master' into multiple_shots_folders

Conflicts:
	README.md
	configs/config.yaml
	lib/wraith.rb
	nojs.js