AES CMAC token generation bug if input data is chunked

[KonsKr]

If the tc_cmac_update() function is called and fills the internal leftover cache completely, the following tc_cmac_final() call will produce a wrong token.

If the tc_cmac_update() is called with a data length which fills up the internal leftover cache completely, the leftover data will be processed instantly and is left empty. This is not the right behavior, because tc_cmac_final() requires that the last block is still in the leftover cache and not processed, because it need special treatment.

See pull request for fix and further information: #52

[KonsKr]

The issue was also addressed in pull request #34