 - struct BGHS - since we have classes - only one structure is created!
 - removed methods: RegisterGridClass, AddGrid, FindGrid, CountGrids
 - BabyGrid::OnSize  - autoresize for fractional part has been blocked (SetSize)
 - Added PaintGrid() to OnSize - no repainting for left grid if main window has been shrinked
 - editing bug? can't edit cells! aha! BabyGrid::GetASCII type of 'returnvalue' changed to 'byte'
 - added method OnSetCaption (moved code from WM_SETTEXT) tocall it from OnCreate
 - added some methods with names same as BGM_*
