added .suo to .gitignore
1. ConvexHullConsole is only a runner. Everything is now in ConvexHull.vcxproj.
This allows to write unit tests.
2. In FindHull add code for 0-2 points. It's a special case because the fullscale algorithm requires at least 3 points.
3. Point structure now has operator== and operator<. They are used in tests for sorting and finding.
4. Add gtest to dependencies so developers don't need to build it on windows.
5. Add a project with unit tests based on Google Test. Few points as well as a square 10 by 10 is tested.