Build system: add --pcert-all option for cert.pl/critpath.pl,
Xdoc: change some macros to do more of their work inside functions, to
reduce the amount of translation necessary.
VL: Updates toward supporting structs/unions/arrays.
 - Datatypes and vardecls are modified to reflect SV notion that each
   variable can have a nettype (or not) and datatype basically
   orthogonally
 - Improved parser support for datatypes and variable decls involving
   datatypes
 - Added (in hid-tools.lisp) routines for looking up types of hierarchical
   names such as struct/array accessors as well as HIDs
 - Added some support for structs/unions in expr-size