Enable warnings for CMake builds and fix some warnings that this exposed. Also add wxUSE_NATIVE_DATAVIEWCTRL option and change default GTK version to 3 for CMake too. See https://github.com/wxWidgets/wxWidgets/pull/1825
Enable warnings for CMake builds and fix some warnings that this exposed. Also add wxUSE_NATIVE_DATAVIEWCTRL option and change default GTK version to 3 for CMake too. See https://github.com/wxWidgets/wxWidgets/pull/1825