Fixed CryptByteBufferTest for iv length.
Fixed -1 that should have been null in CryptByteBufferType
Check for unsupportedType in getIV() in CryptByteBuffer
Fixed comments in CryptByteBuffer
More docs for CryptSig
Merge branch 'ERAT+MAC+CryptBitSet' into GSoC2014-crypto-api
Finished documenting CryptSignature.