[tcltk-perl] Tcl module changes review

[Jeff H. <je...@Ac...>]

Attached is my proposed changes for the Tcl module.  You can
go through the all the changes, but here are the highlights:

* Removed Tcl::GlobalEval, allow Tcl::Eval to take a flags
argument (Tcl_GlobalEval was always just Tcl_Eval with the
TCL_EVAL_GLOBAL flag).  Added Tcl::EVAL_GLOBAL and
Tcl::EVAL_DIRECT constants.

* Added the \300\200 Tcl overlong null encoding handling.  I
did verify that none of Tcl's APIs require it, but when using
in conjunction with Tk, you do need it.

* I'm somewhat bemused by Tcl.xs:prepare_Tcl_result, and the
handling of the gimme var.  If someone would like to explain
this ... I'd appreciate it.

* Tcl::AppendResult is not full Sv <> Tcl_Obj aware.

* t/unicode.t has new tests that exercise unicode transfer at
the Tcl level.  It's modified from Gisle's nul-char.t, and
there is a t/unicode.t for Tcl-Tk as well that interfaces to
the text widget.

Jeff