collectors:
* [new] Added collector to monitor the battery status (bm.py)
* [new] Added collector to interface the IMU sensors (imu.py)
* [new] Added collector to initialize the pwm device (pwm.py)
actuators:
* [new] Added actuator to level the quadcopter using 2 opposite motors. This actuator uses the trapezoidal profile to reach the object of leveling the quadcopter around the 0 degrees (level_trapezoidal.py)

* [new] Added actuator to stabilize the quadcopter using all the motors. This actuator uses the trapezoidal profile to reach the object of stabilizing the quadcopter around the 0 degrees (stabilize_trapezoidal.py)
lib:
* [new] Added library code to control the IMU devices (accelerometer[accel.py], gyroscope[gyro.py], altimeter[alt.py] and magnetometer[mag.py])

* [new] Added common library to access to the I2C bus (common_i2c.py)

* [new] Added common code for general purpuse (common.py)

* [new] Added library code to perform bit operations (bitOps.py)

* [new] Added library code to control the PWM device (pwm.py)
* [new] Added test for the IMU device (IMU-regression.py)
* [new] Added test for the PWM device (pwm-regression.py)
IMU-examples:
* [new] Added examples for the IMU device
Merge branch 'master' of https://github.com/Daniel-Brosnan-Blazquez/DIT-100