Cxxtest to gtest pull request

[Gluttton]

It's a basic version of CxxTest -> GTest migration. Please feel free change (or reject) it.

[Gluttton]

I've removed loops in test cases, because it can be repeated using --gtest_repeat option.

It's transformation hints:

• testSingleSolutionXXX became solve_XXX_IsSingleSolution_Success;
• testValidSolution became solve_XXX_IsValideOutput_Success;
• solve_XXX_IsValide_Success - new tests.

[Gluttton]

I hope attach this pull request to existing issue #3 , but it looks like imposible. Sorry for trash in issue list.