OP-932 Moves the PIOS_PPM_OUT_Set function from pios_ppm_out_priv.h to pios_ppm_out.h
OP-932 Adds a semaphore to PPM input to signal when a new frame has been received.  This can be used to process a new frame with as low a latency as possible.
OP-932: Adds an oplink receiver device, which is based on the gcs receiver device, but uses the OPLinkReceiver UAVObject.  The OPLinkReceiver packets are generated on the OPLink modem.
OP-932 Changes the UAVTalkRelayInputStream function to UAVTalkRelayPacket to allow for not relaying a packet on error, etc.  Also adds a function to get the object ID out of the current packet (UAVTalkGetPacketObjId).  These functions are used by the OPLink.
OP-932 A significant re-work of the OPLink and configuration of the OPLink.  Auto-configuration is removed, and remote modems are bound the coordinator, rather than the other way around.  Timing of the radio link is also significantly changed.  The rfm22b code is also simplified so that it only sends packet, and has no notion about what those packets are, so the rfm22b is converteded to simply a com type device.
OP-932 Replaces the RFM22B PPM/receiver code with an OPLinkReceiver UAVObject.  This object is generated on a coordinator OPLink, and is used by both the OPLink to generate PPM output, and the OPLinkReceiver on the Revo.
OP-932 Adds working one-way mode to the OPLink radio connection.  In this mode, packets will only flow from the ground side (coordinator modem) to the flight side modem.
Fixes the 9600 bps air datarate for the RFM33B modem.
OP-932 Adds additional thread and UAVTalk connection to the telemetry module that reads from the uart/radio link on the Revo.  This allows the Revo to read OAVObjects over both the uart/radio link and the USB link at the same time.  Unfortunately, there's no way to know which link to send UAVObjects out on, so all UAVObjects go to the USB port if USB is connected.  This allows UAVObjects to be received from the OPLink radio, even when USB is connected.
Removes several of the air datarate settings, and fine tunes the calculation of the max packet length from the datarate and packet time.  9600, 19200, 36400, and 57600 modes tested.  Tested 19200 in one-way mode for PPM only.
OP-932 Updates the 19.2 kbps datarate using the spreadsheet.
OP-932 Adds claiming of the SPI bus in the OPLink channel change function.
OP-932 Removed obsolete include of pios_rfm22b_rcvr from pios.h.
OP-932 Adds a direct PPM channel on each Tx packet when in PPM mode, and adds a PPM only mode that uses a 9600 bps air datarate.  Also updates the OPLink configuration tab and moves all OPLink configuration to the OPLink configuration tab on the Revo, and customizes the OPLink configuration tab for the Revo.
OP-932 Forces one-way to be set when PPM only is configured.
OP-932 Fixes the datarate used on PPM only mode, and fixes failsafe on PPM output on OPLM.
OP-932 Fixes raw serial on UART and USB VCP.
OP-932 Allows configuring the Revo as coordinator.
Adds a failsafe on PPM output on OPLink that kicks in when the link goes down.  Also updates all air datarate settings and adds new 64 and 100 kbps modes.
OP-932 Fixes the failsafe that detects when the Rx modem loses sync with the Tx modem.  This was not working on one-way mode.