Changed folder structure
Added PPM decoder
Updated default parameters in PPM decoder
Added SPI device class
MPU9150 driver removed from master branch to archive_mpu9150
Added MPU9250 SPI driver
Added Mahony AHRS application
Added 3D IMU visualizer
Updated README
Added I2C bus select
Added\fixed testConnection() methods in device classes
Added GPS example, Ublox driver
Merge pull request #8 from egorf/master

Added GPS example, Ublox driver
test connection error fixed
Merge pull request #9 from egorf/master

Ublox testConnection() error fixed
Update README.md
Added multithreaded barometer example
Merge pull request #10 from egorf/master

Added multithreaded barometer example
Moved PPM decoder and AHRS to Examples
Fixed PPM decoder