New example with autocomplete-light instead of select2

[jpic]

This is a pretty simple example using the simple autocomplete-light.js web component which offers the following advantages over select2:

• lightweight, 312 SLOCs of JS
• doesn't use jQuery
• doesn't need any "lifecycle code" (the code that initializes etc ... and does not always work ie #1311), because it's a web component
• you can template all rendering output in python, there's no JS template or whatnot, it's like the originial JS script of DAL < v3
• we have full control on it

And the following drawbacks:

• most features from DAL not added
• addanother not added
• in admin neither
• it's a web-component so I don't know perhaps it won't work on some very old browsers

That said, we can start building on that, it's not bothering the select2 implementation code nor breaking compatibility AFAIK.