= polling-based i2c access and mpu6050 code
- referenced from multiwii

= use uint16_t instead of int16_t for timer1 math
- overflow handling

uncomment #define USE_I2CDEVLIB to use i2cdevlib and arduino interrupt-based i2c libs
uncomment #define USE_I2CLIGHT to use the lighter weight i2c and mpu6050 code.