[pymorse] print message if no concurrent.futures

Following the message from Brent Komer <brent.komer@gmail.com>
Fri, Oct 11, 2013 at 6:09 PM on morse-users@laas.fr for Python2.

- add requires=['futures'] in setup.py
  https://pypi.python.org/pypi/futures
- fix typo :-)
[ci] add more test {gps,pose,sick,vw}
[doc] update OSX install w/Homebrew

the Formula moved to the main morse GitHub repo.
[doc] add missing morse-simulator
[doc] reformat Homebrew installation instructions
[builder] An extra scene (MORSE_ENV) is not necessary