PIOS COM: make the interface thread safe

Currently the interface to the FIFO buffer is not thread
safe for multiple threads sending and receiving. This adds
a semaphore on those interfaces.
Android: add serial support for FTDI_FT230X

This is the chipset used in the 3dr radio v2 and should
add support for that radio.
FlightMode: add rate, attitude, and virtual bar

These are explicit modes that will be used like Stabilized#,
but have the benefit of having a clear meaning for things
like GCS. Currently not implemented.
Flight: connect up new flight modes

These are the following hardcoded combinations of channel
settings:

 - RATE:       rate, rate, axis lock
 - ATTITUDE:   attitude, attitude, axis lock
 - VIRTUALBAR: virtualbar, virtualbar, axis lock

The custom modes STABILIZED{1,2,3} are still available like
previously.
Merge pull request #1187 from peabody124/ftdi_pid

Android: add serial support for FTDI_FT230X
Merge pull request #1181 from peabody124/pios_com_thread

PIOS COM: make the interface thread safe
MPU9250 9DOF sensor in SPI mode support
GCS: remove Qt5.2ism

QComboBox::currentData was introduced in Qt 5.2 and all the other
comboboxes in the gcs code use the old

	comboBox->itemData(comboBox->currentIndex());

form anyway. .

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
Sparky: check in assembly page
Merge pull request #1186 from peabody124/sparky_assembly

Sparky: check in assembly page
Remove requirement of NMEA talker ID being 'GP'
Merge pull request #1197 from larsjohnsen/NMEA_TalkerID_all

Remove requirement of NMEA talker ID equaling 'GP'
Merge pull request #1194 from koenkooi/qt5.1

GCS: remove Qt5.2ism
mpu9250: destroy sensor queues when allocation fails
mpu9250: fixed file headers
mpu9250: corrected code style and whitespaces according style guide
Flight: rename flight modes to acro and leveling

Previous commits introduced RATE and ATTITUDE as the name
for flight modes, but this creates ambiguity for the per-axis
settings versus the overall flight mode.

Now the modes are named ACRO and LEVELING, which is consistent
with some of the other software platforms out there. Again, the
original STABILIZED{1,2,3} are still available.
GCS Setup Wizard: use LEVELING and ACRO as default settings
Merge pull request #1191 from strnadda/pr_mpu9250_spi

MPU9250 9DOF sensor in SPI mode support
Merge pull request #1188 from peabody124/flight_modes

Flight modes