Moved transpose after unzip in r2c.
Merge branch 'fft_test'
Freed stack allocations can be reused by subsequent stack allocations.
Implemented recycling of stack allocations.
Added explicit bounds on FFTs.
Merge branch 'master' of https://github.com/halide/Halide
Merge branch 'master' into recycle_stack
Re-enabled computing column FFTs on strips (instead of root).
Reset debug output for allocs to level 4.
create_allocation/free_allocation are now private.
Test to ensure stack allocations can be reused.
Fixed test to be less reliant on undef optimization behavior.
Merge branch 'master' into recycle_stack

Conflicts:
	test/performance/fft.cpp
Merge pull request #366 from halide/recycle_stack

Stack allocation recycling