Change the autoDiscover behaviour

[enyo]

The way we build websites has changed a lot since I started writing this library. I think that the autoDiscover behaviour is more annoying than beneficial.

The addition of the .dropzone class should not be linked to the auto discover behaviour.

What I will change in the next major release:

Instead auf automatically attaching to any form with a .dropzone class, it will have to be marked up explicitly like this (for example):

<form action="/" data-dropzone-auto-discover></form>

I'll find a better name for the property but in essence this is what it's going to look like.

I will then remove the Dropzone.autoDiscover property, and always auto discover these elements.