OP-1510 don't hard code tx_power to 100mW
OP-1522 Robustness of OPLink radio

Increase number of channels to 32 for all bit rates.
Synchronize clock on all channels.
Go into failsafe after 4 or 8 (one_way_link) missed packets.
Don't stay on channel 0 if we dropped a packet.
OP-1526 Apply reverse all motors, tricopter fixes and HexacopterH cleannup
OP-1526 Oups... wrong erase
OP-1526 Do not reverse Yaw tricopter servo with Reverse All motors, the only change is servo neutral. No changes on mixers, ReverveAllMotors is not stored for tricopter.
OP-1526 Better fix : if ReverseAllMotors is checked, store MixerValueYaw as negative value.
Merge remote-tracking branch 'origin/laurent/OP-1526_Reverse_all_motors_not_working' into next
OP-1530 Use rfm22b_dev->num_channels

Use the number of allocated channel from the num_channels field
in the pios_rfm22b_dev struct rather than from the maximum number
of possible of channels given the configured speed.
Merge remote-tracking branch 'origin/havyan/oplink-0' into next
Yaffs2 Library

Base yaffs2 files for Yaffs2 library. Files unmodified to OP environment.
yaffs2 simposix makefiles and posix ramsim

Uncompiled implementation.  Initialised from board init. Yet to be used by logfs.
include stdint
Added missing nandif methods
Added correct nor simulation for simposix
arm compile errors and yaff bug fix

Addressed all arm compile errors
One bug fix for yaffs found from code review
Added pios_stdio.h mapping to yaffs interface methods
simposix integration to pios_stdio file system
simposix yaffs logfs integration
Added debug tracing. Fixed logfs call to pios_open. ObjSave now working.
OP-1532 fix non-ppm mode

Always send packets from the coordinator.
Previously the coordinator only always sent packets
on channel 0. This scheme doesn't work with
with the change to use 32 channel.