fixed twitter bootstrap submodule url
fixed form helper not honoring div attributes

Input options can have a div attribute that according to the latest cakebook can be either a string of classes, or an array of HTML attributes for the div. TwitterBootstrapFormHelper was incorrectly passing an array to Helper::addClass which issues a warning when trimming the string.

I changed it to just pass the div options array to Helper::addClass instead of the whole options array, and changed the rest of the class to use the array form instead of the string form for the div option.
Merge branch 'div-attributes-broken' into develop