Fix erroneously caching SSA vars across kernels in OpenCL C
Build fixes in the modules app
Merge branch 'master' of github.com:halide/Halide
Time opencl kernel launches when gpu_debug is on
Merge branch 'master' of github.com:halide/Halide
Merge branch 'master' into introspection

Conflicts:
	apps/modules/Makefile