Set this variable to a non-empty string to exclude unnecessary
		packages from Tcl build.  This excludes the following packages:
			tcltest

		Additionally, any bundled packages (in the "pkgs" directory)
		are excluded.  This typically includes (as of Tcl 8.6):
			itcl thread

		Also, TclOO is removed from Tcl 8.6 forcefully.


Cross compiling Environment Variables:

	1. CC  
		C compiler   e.g. i686-pc-mingw32-gcc

	2. CXX

		Set this to the name of compiler on the host on which
		the cross compilation is being run.

On Windows we also need this:

	1. RC
		Resource compiler : e.g. i686-pc-mingw32-windres


Kitsh Configure Options:
	1. --enable-kit-storage={zip|mk4|auto}
		Specify which type of storage to use with the Tclkit.  The
		default is to auto-detect.  Auto-detection uses Mk4 if
		available and built statically, otherwise it falls back to Zip.