Version 0.0.13: Support for Verdi interactive.

Switch PROJ.RUNMOD_MODULES to be a dictionary called PROJ.MODULES.
Create SIM.MODULES and VLOG.MODULES to be lists of keys from
PROJ.MODULES.

Set SIM.GUI to be a choice between verdi and dve.
Set simulation executable to verdi for GUI=='verdi'.
Merge branch 'devel' into verdi-inter

Conflicts:
	gadgets/simulate.py
	gadgets/vericom.py
	gogo
	project.py
Check for KeyError

Ensure that any accesses to a MODULES variable will check for the
KeyError exception and exit gracefully.
Only Verdi GUI mode is not yet working.
Switch RUNMOD_MODULES to MODULES dictionary.
Merge branch 'verdi-inter' into devel