Added license.html with third party licenses #13605

 - Made a reasonable header image (Retina)
 - Added the new files to the assembly
 - Refactored the layout of the project, placing relevant files going into the
   package in the "assembly" subdirectory along with assembly.xml

Change-Id: Ibcf0a25e9337e3ab3ae421053032e78b2f5ec882