Add some docstrings

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74083 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Transfer ownership in DataViewEvent.SetDataObject

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74084 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix some compilation errors

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@74085 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775