[imu] default settings for navgo imu
[sim] fix get settings in NPS and other sims

since we directly subscribe to the ivy messages from the GCS, need to listen for
GET_DL_SETTING instead of DL_GET_SETTING
[stm32][ms2100] the reset/set gpio state for the ms2100 reset functionality was inverted, hopefully fixes Issue #384
remove AVR support and unused AVR ground modem

closes #397
remove unmaintained debian and install files/rules
clean trailing whitespaces
[peripherals] add driver for L3G4200 gyro
[peripherals][l2g4200] use i2c_transmit|transceive fuctions