Google Drive / Dropbox FilePicker Portlet.

I added a Google Drive / Dropbox FilePicker Portlet.  The portlet uses the FilePicker API to access Google Drive and DropBox.  Also, I am using bootstrap so I added that to be part of the  "resource sharing" config in pom.
Minor, but for local content it's nice to use the rs:aggregation tag so you can enable/disable aggregation to work with the JS file in a minified or plain format for debugging.  See Javascript Loading at https://wiki.jasig.org/display/PLT/JavaScript+Best+Practices (skin.xml and rs:aggregatedResources tag).  Ignore the part about the CDNs; we don't want CDN URLs in the JSP files yet as we are thinking of handling that another way.  Not a big deal if you don't want to do this.  I had to alter the JSP to troubleshoot the JS issue which is why I noticed.