Add blueimp Gallery web app as git submodule
1. blueimp Gallery is under MIT license, add this as git submodule
2. Add manifest.json to build this app as crosswalk project.
Add the patch file to support presentation feature
The patch contains the feature of using presentation API to display images
in remote display.
Merge pull request #40 from kurli/submodule-Gallery

Add blueimp Gallery web app as git submodule