Slight progress on getting compare tests passing.

Problem is the core of compare is not implemented.
Added missing #pragma once
Added basic status functions
Nice create function
Added initial CMakeLists.txt file
Made CMake actually work
Switched completely from scons to cmake
Implemented branch_compare and ahead/behind reporting for fetch
Switched to debug build type
Added branch names to fetch test repo creation
Fixes suggested by CLion
Temp commit.
Starting to extract test metre code into usable functions.
Ignored .idea and build directories.
Converted merge tests to real tests, added some C wrappers for C++ set<string> for testing