Report trending tags

[theoreticalbts]

This ticket is to report trending in get_state as tags rather than categories.

Here is a summary of the changes:

• Sort based on total_children_rshares2 rather than abs_rshares
• Fix index bug where name is first sort key (should be second)
• Delete trending from category_index
• Add trending to tag_index
• Create tags map which resolves things in tag_index [1]
• Disable unused indexes

This is a slightly breaking change which needs some coordination with the web folks.

[1] Analogous to currently existing categories map which resolves things in category_index

[mvandeberg]

This was merged