WIP changes to enable new voting behaviour
Add hamcrest test dep SBT inexplicably can't find
Lots of WIP changes to promotion/demotion on annotations.

 - More methods on the Promotable trait
 - Extracted a separate backend trait for promotion operations
 - Lots of work on the promote/demote/undo web methods for annotations
 - Front end work on voting notes up and down
Rename/generalise lots of promotion-related i18n keys. Add score details.
Allow facetting by promotion score (negative, neutral, or positive)
Fix lagging rename, missed 'cos of no clean build
Ensure annotations and links produce a creation callback (for indexing)
Bug fixes and refactoring concerning query facets.

 - combining query facets in a tag/exclude union now works
 - multiple query facets are correctly handled as a union by being
   applied within the same fq parameter (instead of multiple)
 - simplification to the filter application code
Use a choice facet for LOD estimation

 - this allows, e.g. using both medium and high LOD
Consolidate rendering of annotations in different contexts.

An enum is now used as a path parameter to specify which one of
field, block, or list annotation rendering is required.
More template work on viewing annotation lists