Nikola Dinev authored Dec 06, 2019 and Tobias Lasser committed Dec 06, 2019

Protect copy constructors in non-leaf and leaf classes, to avoid the implicitly generated ones by the compiler that could cause slicing. In Cloneable, the assignment operator was deleted to disable issues with implicitly generated assingment operators in derived classes to prevent slicing. (resolves #31)

OptimizationProblem is now the new base class 'Problem' for problems, added QuadricProblem incl. conversions between different types of problems, added CG solver