fix a coverage miss in the dsa sig vector loader
Added missing tests for 100% coverage
Merge pull request #953 from Ayrx/fix-cmac-missing-coverage

Added missing tests for CMAC 100% coverage
Merge pull request #952 from reaperhulk/fix-missing-coverage

Fix a bug/coverage miss in the DSA sig vector loader
Added CMACBackend to multibackend
Added tests for multibackend
Added _REASON
Added changelog and versionadded for CMAC
Merge pull request #950 from Ayrx/cmac-multibackend

CMAC multibackend