side mounting on flat fuselage foamies and updated stick config entry method

= support side mounting on flat fuselage foamies.
- you can roll the device left (or right) 90deg and mount it to the side of the fuselage. all other channel wiring, pot settings, axes orientation, etc can remain unchanged.
- you need to inform the device of the new orientation through a stick config option.

= update stick config entry method
- the device assumes the first visited corner is bottom left. then use the sequence 7-9-7-9-7 to enter stick config mode (telephone pad numbering). once in stick config, left = prev config item, right = next config item, up = increase value, down = decrease value (all in the proper orientation).
- there is no need to try the other sequence just because you reverse the AIL or ELE channel. in fact, all of them will now work :), but 7-9-7-9-7 will lead to the natural orientation.

= added new BETA_20130411_* files

= updated the manual at https://docs.google.com/document/d/1Wu7kNyU2rjOpttHuphGEAHgbkrqj7dtaAC7HSnXEutw/pub