Minor refactor of sensorimotor classes

Agents now contain a world and the method generateSensorimotorSequence
Updated tests

Added test for testGenerateSensorimotorSequence
Added assert to check motor encoder parameters are self-consistent.
More cleanup and docs

Code review feedback
Added a few more doc strings
Code review feedback

Move generateSensorimotorSequence to abstract_agent
Some other minor changes
Merge pull request #20 from subutai/minor_refactor

Minor refactor
Merge with master