Including support to C++11

Cmake should now add the respective flags to compilation or throw an
error if compiler doesn't support C++11.
Adding a string parser

This is an initial support to a string parser, which will be called on
TestOptimizer to test for different input instances.
Improving error detail

This should be thought as an alternative to the current form of throwing
errors; it does not mean such verbose explanation should be adopted.
Instead, it is a mere suggestion to be considered.