JS Merge and Minification

Introduced two settings in web.config:

    <add key="UseMergedJavaScriptFiles"   value="false" />  
    <add key="UseMinifiedJavaScriptFiles" value="false" />  

1. UseMergedJavaScriptFiles - If set to true, the site will use a single merged JS file rather than all of the individual custom JS files.

2. UseMinifiedJavaScriptFiles - If set to true, the site will use minified versions of our custom CZ JS files (or custom merged file, depending on the previous setting.)

Production and test sites should usually have both values set to "true". For ease of debugging, development sites can have these values set to "false" (recommended) or can leave them out.

Accompanying this change, a few third party JavaScript  files that the ChronoZoom site hosts have been switched out for their equivalent CDN versions, some of which are more up-to-date. This is to gain an additional minor improvement in load times.

### Additional Information

This branch was started off of the last submission in the Multiple Collections branch, which has previously been submitted with a pull request.