switched to hmac_sha256 using sha256 contexts
Merge branch 'master' into ctx
Switched to context based hmac_sha256
Changed pbkdf2 to use context based hmac and made the optimizations that allowed.
“SHA256 done.  11 tests completed.  0.234844 seconds elapsed.”
massive performance increase as well as all tests passing.
Some contexts weren’t being cleaned, also fixed indents on sha256_test.c
Switched sha256 to size_t variables
speed test for pbkdf2
Merge branch 'master' of https://github.com/iburinoc/ibur-crypto