Lccp

This pull-request is part of the GSOC 2014 project of Markus Schoeler (Automated benchmark generation for object-part segmentation).

It contains an implementation of the lccp segmentation published in:
S. C. Stein, M. Schoeler, J. Papon, F. Woergoetter
Object Partitioning using Local Convexity
In Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2014 

In addition, it contains an example "example_lccp_segmentation.cpp" which shows how to use the lccp segmentation.
Why using custom struct for the edge property here? Won't simple `bool` suffice?