Change legislative items header text

- Note, I used “Items Being Discussed” rather than
  “Items Being Voted on”. Does council vote on every item in Legistar? Are some items presentations? Are some events advisory?
Adds sort-by toggle bits to frontend

- todo: make this actually work
minor documentation and code simplification
Added reasonable zoom limits. 

- We want to avoid space travel when a user accidentally zooms out
Adds a card-like styling to agenda items
Adds number of attachments
Visually separate toggle and content.
Temporarily disable like/share btns to match mockup
Put header text beside type icon 

- also, visually separate from content area below
  with a border
remove old css and extra whitespace
Adds a (fake for now) distance to agenda items
put a date on it

- Adds date of next meeting beneath item header
- Also includes time, but that can be changed easily through the template at the bottom of index.html.erb
- TODO: do we need to show the event location somehow? 
         popup event details or just link to Legistar event page
Adds ability to collapse attachments

- they should all be collapsed by default 
  but there is some weird JS timing stuff going on…
  not worth figuring out now since this will all change
  once the backend bits are setup.
Add sort by activity (comments) to frontend
For the moment, return results w/in last 2 months

- I’m being lazy and don’t want to rescrape legistar
refactor to use mustache template for attachments section

- makes for cleaner / easier to read code
Adds ‘Share your opinion’ bit to frontend (w/o functionality)
bugfix: makes all attachment links work
event fetching and updating
event items update task