Added slightly hacky way of measuring sensor sample rate

The timestamps of the two newest packets received from the arduino are used to
estimate this, giving a very noisy estimate. In any case, it seems to work :).
various changes...?
Converting the graph plotting from processing to python
Data successfully read in from serial port and unpacked into appropriate formats.
Merge branch 'randomp1-testing' into si-testing

Conflicts:
	one_axis_balance/one_axis_balance.ino