Merge pull request #132 from stoewer/master

Account for admin permissions
[model] Add a PositionedModel as a base class for sorting

Sorting is done via the pos (integer) field
[model] Topic is now a PositionedModel
[serializer] +PositionedListReads (implicit) with 'addPositions'

The addPositions method can be used to set the pos field of the
PositionedModel via the ordering of the List.
[serializer] Conference.topic: call addPosition @ deserialisation
[serializer] Conference.topic: sort before serialisation
[views] template: Add jQuery UI and knockout-sortable [js]
[js/model] Conference.topic: don't sort, it is server-side sorted
[views] admin/conference: make topics sortable

Done by using knockout-sortable (which  uses jQuery UI)
Merge pull request #133 from gicmo/sortableTopics

Make topics explicitly sortable (Closes #124)

Cool
[model+serializer+test] Author: convert to PositionedModel
[model+serializer+test] Affiliation: convert to PositionedModel
[test] Topics: add position in Assets
[model+serializer+test] Figure: convert to PositionedModel
[model+serializer+test] Reference: convert to PositionedModel

This is part of issue #106
[less] Add drag-handle icon classes
[views] submission: make references reorderable by dragging
[all] References: +text,+link,-{author, title, year}

This is the second and last part of issue #106.
[views, js/model] References.format(), Add links for text+doi
[views] AbstractList: actually format References