python: Using setuptools 0.8 now
qt5: head branch is no longer 'master'
mercurial: 2.6.3 & use depends_on :python

* The `hg` binary is installed in `$(brew --prefix)/bin/hg`.
* Optional docs (hg help will still work) so that docutils is not
  needed.
* The `depends_on :python` is needed for software that needs
  the `Python.h`.

Fix #20929
update elixir formula to 0.10.0

Closes #21224.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
devel node 0.11.4

Closes #21220.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
qt5: -sdk no longer needed.

* Qt5's can detect this itself, now. This is good.
* HEAD no longer has the `-nomake demos`.
qt5: Fix dbus

Fix #21221