Python ctypes interface

This implements a scriptable interface through a (minimal) ctypes/python implementation of RunControl, DataCollector and a Producer.

Currently supports:
- RunControl: Configure, Start, Stop runs
- DataCollector: Instantiate
- Producer: React on Configure,Start/Stop Run Commands, send raw data packets

Build with ```cmake -D BUILD_python=ON ..``` and run by executing one of the example scripts in the ```python``` subfolder in the EUDAQ root.

Todo before merging:
- [ ] add documentation
- [ ] test with Windows
- [ ] test with OSX

This is a proof-of-concept or minimal implementation to address issue eudaq/eudaq#38