migrate relations to ui-select

Have gone ahead and merged. We can discuss improving ui-select keyboard
support separately.

On Monday, December 29, 2014, Mihail Maxacov <notifications@github.com>
wrote:

> In
> frontend/public/templates/work_packages/tabs/_add_work_package_relation.html
> <https://github.com/opf/openproject/pull/2390#discussion-diff-22322221>:
>
> > -         name="relation[to_id][{{ handler.relationsId }}]"
> > -         size="10"
> > -         type="text"
> > -         autocomplete="off"
> > -         ng-model="relationToAddId"
> > -         required
> > -         focus="focusElementIndex === -1">
> > -  <div id="related_issue_candidates-{{ handler.relationsId }}"
> > -   class="autocomplete related-issue-candidates"></div>
> > +  <ui-select
> > +    id="relation_to_id-{{ handler.relationsId }}"
> > +    name="relation[to_id][{{ handler.relationsId }}]"
> > +    ng-model="$parent.relationToAddId"
> > +    required
> > +    theme="select2">
> > +    <ui-select-match>{{$select.selected.to_s}}</ui-select-match>
>
> @myabc <https://github.com/myabc> that we should discuss because TAB is
> not very useful in ui.select's layout and we should either come up with
> some hotkeys or maybe tab go through ui.selects elements (I don't know
> which is worse)
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/opf/openproject/pull/2390/files#r22322221>.
>