Experimental branch that reverts to no system includes for the runtime

Trying to debug an issue with pnacl clang 32-bit on windows
Was still including system stdint
Fix ifdef in buffer_t
Update nacl version

Required removing -O3 from runtime module compilation. Shouldn't matter
because they get optimized later.
Windows build fixes
Merge branch 'master' into no_runtime_includes

Conflicts:
	test/scripts/distrib_windows.ps1
Update runtime_internal for newer clangs
Turned off ms compatibility mode on runtime compilation (which breaks cross-compilation). Also turned off exceptions
Windows build tracks llvm trunk again
Merge branch 'master' into no_runtime_includes
Merge branch 'master' into no_runtime_includes
Correct comment about native client in the readme

We no longer need the sdk to compile the runtime modules.
Update llvm version number for trunk in windows distrib
Fix missing deps and race conditions in HelloNaCl Makefile
Fix deps and race conditions in nacl_demos Makefile
Merge branch 'no_runtime_includes' of github.com:halide/Halide into no_runtime_includes
Fixed link to native client SDK
Merge branch 'master' into no_runtime_includes

Conflicts:
	README
Merge pull request #407 from halide/no_runtime_includes

No runtime includes
Fix for: Relative paths in InitialModules build break CMake / Xcode #408