added new 20140212_RX3S_V2_AILR_IN_ON_RUD_IN.hex

use RUD_IN pin for AILR_IN input. this will allow rudderless planes to use dual ailerons without any hardware mods. RUD_OUT will be neutral (1500us) + yaw stabilization.
minor fixes

- slightly simpler lock-free test and assignments
- renamed duckeron surfaces to LEFT1/2 and RIGHT1/2
Merge remote-tracking branch 'remotes/origin/master' into new_mix

added RX3S_V2_AILR_IN_ON_RUD_IN.hex image