Layout responsive events list and event details pages

[themightychris]

As part of #138 two new pages are being added to laddr:

• Browse Events: http://laddr-v2-dev.poplar.phl.io/events
• Event Details
  • Upcoming event we'll be promoting: http://laddr-v2-dev.poplar.phl.io/events/city-as-a-service-2016
  • Recent event with full schedule input: http://laddr-v2-dev.poplar.phl.io/events/sustainability-2015

Here's a fully-featured event on the old site we're deprecating: Almost fully-features event page from past hackathon on the appsforphilly site we're deprecating: http://appsforphilly.org/events/transportation-2015

The most immediate use case will be using the direct link to the upcoming hackathon for promoting it. Key elements include:

• Prominent date, location
• Long markdown content area with multiple headlined main sections
• Detailed one-day or multi-day schedule
• Small list of subpages with detailed information about the event
• Gallery of sponsor logos
• Idea board or preview with link to full idea board page
• Gallery of RSVPd attendees
• List of links to projects founded for the event

If it sounds like a party flyer, it kind of is... but maybe could be less so