Need a way to control property/event display based on wxWidgets version

[KeyWorksRW]

Description:

There needs to be a way to limit events that are only available with specific versions of wxWidgets. For exampe, EVT_WEBVIEW_NEWWINDOW_FEATURES is only available with wxWidgets 3.3. It might make sense to add an attribute in the XML declaration files that specifies a specific version for an event or property. We could then choose whether or not to display it in the property grid. Of course this would be additionally complicated by the language -- e.g., wxWidgets 3.1 and 3.3 are only available for C++, whereas wxPython and wxRuby3 currently only support 3.2.