Update tools.mk

Download directory/file changed for openssl windows version.
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.
Merge pull request #1180 from joergrohde/patch-1

Update tools.mk
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.
AltitudeHold: tune the amount of tilt compensation

The existing code would still drop during forward flight,
because of the non-linearities of open loop ESCs. This
allows tuning the amount of tilt compensation.
AltitudeHold: make compensation amount a uint16

Being able to only go to the power 2.5 was insufficient to
maintain forward flight at steeper angles.
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