Upgrade wxwidgets to latest 3.3.2 from https://github.com/SoftFever/Orca-deps-wxWidgets/tree/v3.3.2
our current version is quite old(3.1.5) with some custom patches which we expect are not needed anymore for latest wxwidgets version. 
1. check wxwidgets's document to figure out what API have changed from 3.1.5 to 3.3.2
2. plan the upgrade and use practical approaches, avoid making excessive changes.