Branch for rewriting TclCompileScript() and related routines, with the
intent to generally simplify and make more readable, as well as find and
eliminate duplication with ensemble machinery and improve mergeability
to other branches.  Work in Progress.  Doesn't work at all right now.
merge trunk
Nearly functional now, but leaky and not yet as tidy as I'm hoping for.
merge trunk
A few bug fixes from failing tests; still leaky.
Fix bytecode ranges in the cmdMapPtr.  still leaky.
merge trunk
merge trunk
plug memory leaks
merge trunk
Stop the compileProc routines leaving behind error messages in interp.
(Nicer way to solve [Bug 20a81392ec].)  Make simplifications in 
TclCompileScript() make possible by the new structure.  Still a work
in progress.
More elimination of error message litter to fix [Bug 20a81392ec].
More Work In Progress.
comment improvements
merge trunk
merge trunk
merge trunk
The routines StartExpanding() and EnterCmdWordData() are orthogonal, so it's
ok to reverse the order in which they are called.
Consolidate the StartExpanding() calls.
Defer expansion request detection as much as possible.