Generic macros to mock method/function pair

• Updated to build with newest Google Test (commit 6c5c4554).
• Introduced two generic macros CMOCK_MOCK_METHOD and CMOCK_MOCK_FUNCTION to mock method/function pair.
• Deprecated use of MOCK_METHOD/CMOCK_MOCK_FUNCTIONn macros in favor of the new generic macros.
• Introduced CMOCK_REAL_FUNCTION macro to call a real function.