major changes:
-supports Python decorator syntax for generators (needs 2.4)
-intbv() doesn't have a default anymore
-many improvements to Verilog conversion
changes:
* VCD output for waveform viewing
- function additions
- needs Python 2.3, 2.4 is OK
* Conversion to Verilog to provide a path to implementation
* Added cosimulation support for the cver Verilog simulator.
- bugfixes