Add Makefile rule to build a binary distribution
Merge branch 'master' of github.com:halide/Halide

Conflicts:
	Makefile
Further allocation refactoring in CodeGen_Posix

Now we reuse old stack space via a best-fit (or even not-quite-fit)
algorithm. If we don't quite fit we rewrite the old stack allocation
to be larger.
Merge branch 'master' of github.com:halide/Halide
Reintroduced cleanup-on-bailout code.
Removed some complaints due to clang's integer sanitizer.

These almost certainly weren't bugs, but they were hard enough to
think about that I just made it slightly more explicit.
Merge branch 'master' of github.com:halide/Halide
Merge branch 'master' into nick-sandbox