o Adjusted spin control size/placement (On Windows ctrls were overlapping).
o Set Ok/Cancel buttons to wx.ID_OK & wx.ID_CANCEL to provide default dialog
behaviour.
o If no date has been clicked clicked, OnOk set the result to calend's date,
important if keyboard only navigation is used.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@33636 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775