Nice to have: .select2-search input {background-image} reflect refresh() action in progress

[dimylik]

Nice to have indicator, that refresh() action is in progress, instead of magnifying glass, show something like loading icon in search input.
This will indicates that something is going on.

Also, you could extend that, and if refresh() action does not return anything, show another icon, like cross or something

like:

.select2-search .refresh-in-progress input {
background-image: url('loading.gif')
}

Version of Angular, UI-Select, and Bootstrap/Select2/Selectize CSS

Angular: 1.49

UI-Select: "0.17.1"

Bootstrap: 3

[user378230]

Closing as duplicate of #919