STM32F30x - Add support for I2C2.
STM32F30x - Add support for UART3 - untested.
Whitespace cleanup.
Add MPU9150 driver.

This is a almost a complete clone of the 6050 - needs cleanup and
de-duplication.
Support the Sparky board by peabody124 - work in progress, not flight
ready.

https://github.com/TauLabs/TauLabs/wiki/Sparky

http://buildandcrash.blogspot.co.uk/2013/05/sparky-testing-and-building-no-crashing.html
Fix comments in system startup files.
STM32F30x - Fix uart3 pinsource definitions

UART3 RX/TX working on sparky.
STM32F30x - Allow overriding of USARTx GPIO pins from target.h.

USART1 RX/TX now working on Sparky.
SPARKY - Update UART2 configuration.

UART2 RX working using SumD.
STM32F30x - Fix GPIO initialisation.

Closes #154
SPARKY - Use RX_PPM by default.
SPARKY - PWM output on PWM1-10.
SPARKY - Adding documentation.
SPARKY - Adding note regarding the TauLabs bootloader.
Reset navigation if sat count is too low.
GPS page on the display to aid GPS outdoor testing.
Fix gps error counter so that it is meaningful, it was being reset each
time the gps unit was reinitialised leading users to think there were no
GPS errors.
GPS - minor code readability improvements.
GPS - adding a fixme regarding 'ap_mode' variable.
GPS - cleanup nagivation reset flag usage.