Packaging pi code

[patchedByBatman]

Main Changes

Packaging Python code running on Pi. Below is the changes list:

1. Moved folder raspberry/estimators to raspberry/bzzz/estimators.
2. Moved folder raspberry/read_sbus to raspberry/bzzz/read_sbus.
3. Moved folder raspberry/simulations to raspberry/bzzz/simulations.
4. Some minor code changes.

Associated Issues

None

Tests

Just repacking existing code.

[alphaville]

I'm not sure when/whether the altitude KF was reviewed, but here are a few comments from my side:

• [x] the constructor returns an object of type bzzz.estimators.KalmanFilter, not None
• [x] the constructor requires documentation
• [x] I would rename run to update
• [x] ~In run rename Tt to something more understandable (thrust_ref?)~ (later)
• [x] change 10**-3 to 1e-3 (same for 10**-5)
• [x] ~self.__cache_MU_values: why is this a lambda?~ will be addressed later
• [x] MU_cache - rename to measurement_update_cache
• [x] ~how does this implementation of the KF handle missing values?~ (later)