Keep DropDownButton pressed if PopupWindow is visible
GetDatePickerThemeButtonMinTextSize included date and time what caused the calculation of the dropdown icon size from the control's width to be incorrect
Redirect WM_KEYDOWN/WM_KEYUP/WM_CHAR to the popup calendar if it is visible but doesn't have the focus. (related to TJvCustomDatePickerEdit.ShowPopup change in 8abf6c3d2d31ae99b568fed0d874277d2b04f928)
* Updated DropDownButton theming for Vista or newer.
* DropDownButton hot state is only used if mouse if over the butten
Added Vista+ theming support for older than Delphi 2009 versions