0.2
 * graphics resources are properly released
 * added BMA-150 accelerometer driver
 * added AK8975 compass driver
 * sophisticated makefile
 * main.c split to a new application module
 * global configuration moved to config.h
 * merged graphics framework, new graphics API
 * all geometry is stored in vertex buffer objects
 * added NMEA 0183 RMC sentence, added global labels (altitude, speed, track angle)