Feature/folder select

@alex-deaconu Please review.  

The storage selector now has the standard buttons from style guide and can return multiple files/folders if selected.  The calling window can do what it likes with all those selections.  

This isn't yet enabled for the RVA modal, that stays the same.

[http://192.254.220.35/storage-client-builds/folder-select/storage-full.html](Test Environment)
[http://rva-test.appspot.com](RVA stays the same)