improve icons for zoning, subdivision plats

[techieshark]

Currently we use a cog icon for things that don't have a better icon. For zoning issues and subdivision plats, it seems like we should be able to find a better icon than this:

(Screenshot from District 6)

I don't see any great ones in Font Awesome so this is a little harder than just replacing a fa-something class in the html with fa-something-better. We could pull in icons from Noun Project though.

Some Noun Project icons that might work:

• Construction (house)
• Nail Head (might evoke subdivision also?)
• Construction Vehicle (has advantage of being public domain)

[techieshark]

Thoughts on implementation:

Currently EventItem.render() does some transforms to make the title a bit more readable. We could move that to this function which gets called before render(). In the code that figures out if an Oridinance is a zoning ordinance, it could also create a EventItem.item.matter_subtype property and set it to 'zoning', and then when we set the icon here we could choose a better icon if matter_subtype is set.

A couple other thoughts:

• doing the transforms in Rubyland would make for simpler javascript, although that gets us further from having javascript code that others could rip out and use with either our data or data directly from the Granicus API.
• we'll probably need to update the CSS to bring in stuff from Noun Project (and if we use CC-BY icons we'll need to properly attribute them)