Added techlibs/common/pmux2mux.v
Some improvements in log_dump_val_worker() templates
Added setundef command
Improved setundef random number generator
Added $bu0 cell to simlib.v
Removed cases of trailing comma in stdcells.v
Merge branch 'master' of https://github.com/cliffordwolf/yosys
Merge branch 'master' of https://github.com/ahmedirfan1983/yosys