Hello Guilers!

The attached patch makes `compile' and friends use fresh module rather
than the current module as the default compile-time environment.

The intent is to make sure macro definitions and side-effects made at
expansion time do not (to some extents) clutter the current module's
name space.

However, assignments to global variables made at expansion time do have
a visible effect on the running system.  This is because the compiler
and "compilee" share the whole module hierarchy, down to the pre-module
obarray.

Comments?

Thanks,
Ludo'.