CMakeLists.txt: Add Windows support
Adding find modules originally developed in TangoDatabase!64 (merged). These find modules support Windows.
By default FindTango.cmake will use pkg-config, this can be disabled by setting -DTango_USE_PKG_CONFIG=OFF. If pkg-config cannot find tango, then FindTango.cmake will then fallback to searching the system using cmake find_*() calls. When not using pkg-config directly FindTango will recursively look for dependencies using find_package().
Other find modules will only use pkg-config to provide hints of where to look.
Working towards TangoTickets#61 (closed)