Checkpoint base state of initial redo.
Checkpoint as this is plausible and semantically correct though still way inefficient.
Checkpoint again.  Easy to claim code was plausible when it was secretly left untested.
Checkpoint again.  Fused intermediaries between grayScale and detectEdges.
Checkpoint again.  Added PA variant for computeEnergy.
Remove unneeded temp buffers post-intermediary-fusion.
Fix typo in soon-to-be-used code..
Lifted `context` param out to invocation context.
Checkpoint.  Things may have magically gotten faster or maybe it is just that I restarted my Firefox.