Added heat stencil and matmul assembly
Added Readme for heat stencil and matmul_assembly
Updated readme for heat_stencil and matmul_assembly
Updated readme for heat_stencil and matmul_assembly
Updated version of heat_stencil and matmul_optimized
Merge pull request #25 from anishva/master

Pull request to merge source code of heat_stencil and matmul_optimized