Pat showed me a patch that reduced CCS runtime by 35%.  This is a
modification of his patch, focusing solely on reducing the number of
matrix accesses in the "extra" calculations in the SSE recursor.

[Tracking bug 21562]

[git-p4: depot-paths = "//depot/software/common/ConsensusCore/": change = 118438]
Fix mistake in the boundary conditions handling in the last changeset.

[Tracking bug 21562]

[git-p4: depot-paths = "//depot/software/common/ConsensusCore/": change = 118484]