fixing multiPPM/PWM maps for CJMCU
Update gps.c

correctly verifies checksum before modifying read NMEA gps data
Merge pull request #152 from norem/master

Correctly verifies checksum before modifying read NMEA gps data
making nmea checksum patch comply with baseflight coding / indentation style
Make it build
Merge pull request #154 from davibe/master

Make it build
Revert last makefile change - wasn't needed, user error.
building hex with latest changes - improved althold; improved NMEA parser; other misc fixes
building hex with latest changes - improved althold; improved NMEA parser; other misc fixes
Adding remainder of CJMCU support
revert makefile change, that was mistake
cleanup hardware revision detection and get rid of checks for hse_value
add spi autodetect functionality, actually check for currently used M25P16 flash chip
Get rid of rev4 PB13 usage
FrSky telemtry: Put Vfas battery voltage in again
Merge pull request #157 from cody82/master

FrSky telemetry: Put Vfas battery voltage in again
Initial stab at supporting MPU6500.
Make I2C driver fail gracefully when I2C hardware hasn't been initialized (on boards w/o I2C sensors)
Also fixes CJMCU build target to include SERIAL_RX features.
Add support (untested) for remapped USART3 w/DMA transfer
Update README.md
Slight cleanup of MPU6050 driver to use same constants as MPU6500. Both drivers should probably get merged, the operation is nearly identical with only bus access being different.
It helps to enable clock to correct peripheral (Fixing USART3 APB1)