Replace initialization "hack' with a proper event listener

[markhalliwell]

https://github.com/truckingsim/Ajax-Bootstrap-Select/blob/master/src/js/classes/AjaxBootstrapSelect.js#L246-L251

This code uses a setTimeout in a very hack-ish way (basically, hope that bootstrap-select has been initialized first within 500ms). This is really unreliable and should be listening for an event instead.

We're actually waiting for the bootstrap-select project to create an initialized event that they themselves will trigger after their plugin has been created (see snapappointments/bootstrap-select#1026).

This will allow us to ensure that bootstrap-select has indeed initialized before attempting to initialize our plugin.

[truckingsim]

Looks like this has been added and will be part of 1.7.0.

[markhalliwell]

Indeed, as loaded.bs.select. Also, makes me wonder if we should be doing any sort of "version check"?

[truckingsim]

I think we'll have to on this update as it won't work without the events. It looks like they expose the version so should be easy to add.