Makefile got one external option:
- TCLTK_PATH: the path to the Tcl/Tk interpreter.
Users (or build wrappers) may set this variable to the
location of the wish executable.
Signed-off-by: Eygene Ryabinkin <rea-git@codelabs.ru>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>