Workaround to mitigate the severe memory leaks that plugin_host suffer when objects are shared betwen threads. In the API doc of ST3 they said those _async methods are thread safe, but the objects that are created in local scopes into that functions are not being collected by the ST3 embedded python garbage collector and severe memory leaks appears much more often if your plugin is hardly based on asynchronous events (as anaconda is). This meant to solve (or at least strongly mitigate) the #97 issue