* Clean up formatting and make OK button the default in the array dialog.
* Make the OK button the default in the move exact dialog.
* Change the directory picker control from wxGenericDirCtrl to wxDirPickerCtrl so the native
directory picker dialog is used to select the directory in the select pretty library path dialog.
* Make the OK button the default in the select pretty library path dialog.
* in file/library save as..., remove option to save a lib under the legacy format (which is not possible and creates an error message)
* if the current loaded lib is a legacy lib, when the user try to save or delete a footprint, displays a message which explains what the user should do.
* add a suitable dialog to select/create a .pretty folder library (a file dialog or a dir dialog coming from wxWidgets is not friendly usable.)