Use a consistent font in the default config
remove duplicate code
add support for more colors in the gradient
Make tests more robust (again)

- Kill Xephyr if qtile doesn't start

- Wait for Xephyr to come up or for Xephyr process to terminate
  (possible cause for hang if Xephyr comes up, but with wrong DISPLAY or
  xcb problem)

- Wait for qtile to respond or error out using pipes (possible cause for
  hang if qtile gets caught in a loop before able to respond to status()
  call)
Add short sleep after rotate and resize
Add long timeouts to tests in case things go unforeseeably wrong

Closes #454
Fix handling of messages and the systray

- Properly handles incoming messages (let xcb drop high bit on
  response_type)

- systray parses ClientMessageEvents "properly" (use event.type and
  event.data)

- systray only tries to set icon for `SYSTEM_TRAY_REQUEST_DOCK` messages
  (see
  http://standards.freedesktop.org/systemtray-spec/systemtray-spec-latest.html)
Merge branch 'develop' into cffi

Conflicts:
	libqtile/drawer.py
	libqtile/widget/systray.py