[ccore.cluster.bang] C/C++ BANG implementation

[annoviko]

Introduction Clustering algorithm BANG is implemented using python. This algorithm should be supported by CCORE (C/C++ implementation) to increase performance of the algorithm.

Description Following task should done in scope of this issue:

1. C/C++ implementation of the BANG algorithm. Design from python implementation can be reused (see pyclustering.cluster.bang).
2. Unit-tests for C/C++ implementation.
3. Interface implementation between C/C++ and python parts.
4. Integration tests for the algorithm.