Alternative solution to fix #3880: unselect everything before associating a model.
Improve solution for #3880: don't prevent associating the same model again, it's causing problems in ModelSelector.
Fix EntityInspector not receiving mousewheel events when not explicitly in focus (at least in wxMSW).
Language fix and translation update.
Activate the scroll event catcher at a global level (#3894)

Events are now redirected to the window below the cursor at all times.
Rewrite SoundChooser population code to use threading.
Fix #3896: SoundChooser doesn't show current entity's value.
wxutil::TreeModel variables are stored as wxObjectDataPtrs intead of raw pointers

Should reduce potential for errors in IncRef/DecRef calls.
Added missing Automake-generated scripts
Fixed crashes in ModelSelector on Linux

- TreeView is not created until after the models list is populated and the
  TreeModel is ready to be associated. Leaving the TreeView without a model
  seems to cause a crash when the progress dialog triggers idle event
  processing.
- Removed AssociateModel(NULL) call on shutdown, since this causes an immediate
  crash on Linux. Instead the TreeView is simply destroyed.