* acinclude.m4: Include ../config/tcl.m4 to pick up
standard Tcl configury bits.
Remove all Tcl, Tk, Itcl, Itk, etc definitions.
* configure.ac: Don't check if ../itcl exists when building
gdbtk. It could be installed.
Rewrite gdbtk configury to allow for using system-supplied
Tcl and Tk. Gdbtk no longer requires build-time access to
itcl and itk.
* Makefile.in: Remove everything related to itcl and itk.
Rewrite the Tcl bits for gdbtk to correspond to rewrite of
configure.ac.
Remove v850ice.o build rule.
(ALL_TCL_CFLAGS): New convenience defintion. Change all
gdbtk sources to use it.
* configure: Regenerate.