Added a drop-down box to doc to switch between stable and unstable

Similar to what docs.python.org does to switch between Python releases.
This relies on a fairly stupid {stable <-> latest} URL replacement.

While here, changed the title of documentation to 'The MORSE Simulator Documentation'
[cmake] Mark the project stable if we are in a _STABLE branch
[camera] Fix camera handling for blender version < 2.65

The groupMembers api has changed of name several times so deal with it.
Moreover, this API has been added only in 2.63 so 'deal' with it. In
this case, there is no proper way to handle 'grouped object' so #509
will still be an issue.
[mw] socket reader must return a boolean

Must handle #544 for socket
[middleware/pocolibs] datastream reader must return a bool

Handle #544 for pocolibs
[middleware] moos actuator datastream handler must return bool

Handle #544 for MOOS
[bin/morse] 2.71 seems to works fine for Morse
[cmake] Prepare for 1.2.1
fix to Fix #459 for pr2 to work with MotionXYW