Added bmrmopt class in shogun/optimization/framework

@vigsterkr @karinapf
This is the first class in the framework. Other bmrm solvers can be extended quite easily by inheriting bmrmOptimizer class. Will add those classes soon under shogun/optimization/framework.
A brief overview of files:
1. functions.h - Contains classes for the QP function (square-norm dual)
2. constraints.h - Contains data about the constraints. (Previous implementation contained only simplex constraints. Will change that.)
3. CP.h - Contains structures for cutting planes.
4. bmrmopt.h - Contains the BMRM solver with these three classes.