Fix `Error: Failed to initialize GUI: no built-in themes found` when run gui and load theme, by add WX_USE_THEME in the place that create them object
Ensure that wxTestableFrame is shown on the (main) screen. changed by VZ, add here first, for SOC2014_UNIV branch, when the probject finished, merge it
GetLabel should return the original label that with mnemonics, the original label stored in wxControlBase m_labelOrig, get it by wxControlBase::GetLabel()