Have gogo create flists on its own.
Change all print functions to use Python3 version of print.
Add check_files_exist function for gadgets.
Add vcfg.py files to each vkit. Have the vkit class read this file
in to determine values for the VKIT.
Clean up pymake, and give it a cache of prior results, with abspath
names.
Change the entire structure of gvars to host module variables instead
of one huge dictionary.
Move utilities out of gvars and into utils. Move other funcs out of
gvars and into gogo.
Move some vars out of SIM.
Add +ntb_random_seed to command-line for simulation.
Merge branch 'cmd_line' into devel
Merge branch 'devel'