Merge pull request #6 from Dr-Emann/support-renderscript

Support renderscript
Update README.md
Fixup README.md

A space was missing when indenting the code to process with
renderscript. This made it not show as code.
Remove more build artifacts

Removed StackBlur/obj. This folder is autogenerated when ndk-build is
run
Remove unused resources from StackBlur library

None of the resources in the library were in use anywhere.
Move to newest version of the gradle build system