WIP on parsetree
unfinished work on parsing generate blocks
added parser for generate stmts and integrated it with modules
work on parsing interfaces
Merge remote-tracking branch 'remotes/origin/master' into generate

Conflicts:
	books/centaur/vl/loader/parser/modules.lisp
parser tests working, although none yet written for generate, modports, interfaces
fix json support (as yet incomplete for generate stuff)
fix ports problem
VL: Add support for parsing SystemVerilog interfaces and generate blocks.
(Merge to complete feature branch.)