Add REDConvolve.{h,m}
Stub in convolution.

This doesn’t actually implement it yet.
Doomed attempt at fauxroutines.
Yeah, that ain’t happenin’.
Implement a strict right-reduce.
More semantic.
Enumeration enumerator.
Test the enumerator.
Merge branch 'master' into convolution
Typedef the enumerator state.
Parameterize refilling with the state.
Parameterize refilling with the collection.
Refilling can now be static.
Add Obstruct.
Remove the array convolver.
Implements convolution in terms of iterables.
Extract the iterable protocol to its own header.
Add a typedef for iterators.
Move the fast enumeration iteration into its own file.
Publish the fast enumeration iterator.