Implement basic methods for mixer
Implement classes for pounder
Merge branch 'implementation'

* implementation:
  Implement classes for pounder
  Implement basic methods for mixer
Fix way to get weight in Scale.cpp
Merge branch 'implementation'

* implementation:
  Fix way to get weight in Scale.cpp
Implement Subject.cpp
Merge branch 'implementation'

* implementation:
  Implement Subject.cpp