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 #108 from quiaro/master

Improves load time and adds config file instructions
Merge branch 'master' of github.com:craftercms/social into 2.3.x
Merge branch '2.3.x' of github.com:craftercms/social into 2.3.x
Merge branch '2.3.x' of github.com:craftercms/social into 2.3.x
CRAFTERCMS-644 Comment attachment error messages display nested exception information
Merge pull request #119 from cortiz/2.3.x

2.3.x