Deletes unused js files and loads minified files for improved load time

Also, adds check to avoid js error (missing targetUrl's value would
throw a js error -controller.js)
Adds config file instructions
Merge pull request #111 from cortiz/2.3.x

Backport Commit e29c637 to 2.3.x branch
Merge pull request #112 from quiaro/2.3.x

Improves load time and adds config file instructions