gitk: Ignore gitk-wish buildproduct

gitk, when bound into the git.git project tree, used to live at the
root level, but in 62ba514 (Move gitk to its own subdirectory,
2007-11-17) it was moved to a subdirectory.  The code used to track
changes to TCLTK_PATH (which should cause gitk to be rebuilt to
point at the new interpreter) was left in the main Makefile instead
of being moved to the new Makefile that was created for the gitk
project.

Also add .gitignore file to list build artifacts for the gitk
project.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
INSTALL: git-p4 does not support Python 3

Signed-off-by: Junio C Hamano <gitster@pobox.com>
git_remote_helpers: remove GIT-PYTHON-VERSION upon "clean"

fadf8c7 (git_remote_helpers: force rebuild if python version changes, 2013-01-20)
started using a marker file to keep track of the version of Python interpreter
used for the last build, but forgot to remove it when asked to "make clean".

Acked-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge git://ozlabs.org/~paulus/gitk

* git://ozlabs.org/~paulus/gitk:
  gitk: Ignore gitk-wish buildproduct
Merge branch 'jk/remote-helpers-in-python-3' into next

Finishing touches

* jk/remote-helpers-in-python-3:
  git_remote_helpers: remove GIT-PYTHON-VERSION upon "clean"
Merge branch 'bc/git-p4-for-python-2.4' into next

With this, we are (and we will be) incompatible with Python 3

* bc/git-p4-for-python-2.4:
  INSTALL: git-p4 does not support Python 3
Merge branch 'master' into next

* master:
  gitk: Ignore gitk-wish buildproduct