pycrc 0.4 released

New parameter sets. pycrc handles now the following models: crc-8, crc-16, citt, kermit, x-25, xmodem, zmodem, crc-32, crc-32c, posix, jam, xfer.
Added option to calculate the checksum from a file.
The generated C source is now documented in a in a Doxygen-style format.
Promoted the program to Production/Stable state.