added working SplitImage experimental Privly App

This is a proof-of-concept application for sharing images via HTML5 file APIs. It pipes the images through the ZeroBin style of encryption so the image is not stored in cleartext.

TODO:

* Write up a better readme
* Add a file form in addition to the drag and drop UI
* Move the ZeroBin libs into the vendor director so they are not duplicated between the apps
* Test the application on more platforms from the hosted context