Build Failure: GIT-GUI-VARS

"make all" fails with "NO_TCLTK=y" because gitk-wish depends on GIT- 
GUI-VARS which is defined inside the ifndef block.

AFAICT, either gitk-wish should be moved inside a ifndef block or an  
else should be added with a phony GIT-GUI-VARS.  I don't know which  
is preferred.

Actually, I can't tell why make is trying to build it in the first  
place.  :-/  gitk-wish is added to OTHER_PROGRAMS inside a NO_TCLTK  
block. (Debian oldstable, GNU Make 3.80, git repo v1.5.2-rc3)

And, while I'm poking through here, there's a line labeled "Backward  
compatibility -- to be removed after 1.0".  Git IDs itself as  
1.5.2.rc3.  Isn't that after 1.0?  :-)

~~ Brian