Update Cmake files.
Use C++11 to delete copy constructor.
CMake: add all cpp files to the library.
IP class gets a protected interface to some internals.
Pimpl class Sum.
New hard Sudoku
New version of Catch.
Fix for GCC 4.8.
IP::add_variable_as_boolean
Support Minisat as external solver.

Still very limited functionality.
Enumerate solutions with Minisat.
Use OpenMP for wall time.
Catch as a library for faster compilation.
Allow silent mode without stdout
Program to read and solve file from NSPLib