python3: --with-brewed-tk needs :x11 if --with-x11

When tcl-tk was installed `--with-x11`, python needs
to `depends_on :x11`, otherwise tcl-tk ships an
included versions of X11.
New formula zpython: Zsh Python Module

This formula provides a zsh python module that allows executing python
as a zsh builtin. Its current main purpose is speeding up heavy
prompts like powerline.

It requires at least zsh 5.x.

More info: http://www.zsh.org/mla/workers/2013/msg00089.html

Closes #20182.

Signed-off-by: Samuel John <github@SamuelJohn.de>
Revert "python: Remove outdated fix"

This reverts commit 59ebdf67cfa5cd8fcc6661e180e3bab2ab2ed6fb.
zpython: Comments, version number & minor stuff