Added SRFI-111 and R7RS-large boxes
Added uname procedure (preparing for SRFI-112)
Added SHUT_* in windows environment.
Added document for CMAC and some bytevector utils.
Added document for SRFI-111 support
Added <mac> interface to (crypto) for MAC.
Added c-variable macro to get C defined variables.
modified c-variable behaviour a bit. (not final yet).
Modified c-variable thing.
Modified REPL to handle custome current-exit.
Added NULL check for getTemporaryDirectory.
Merge