Add a past boot camps toggle button to map.

Also made past boot camps *not* show up by default.
Merge pull request #204 from gvwilson/2013-01-vt

Adding Chris Lasher while updating the Virginia Tech boot camp page
Adding drop downs to Boot Camp, Blog, and About menu items.

Dropdown menu items are:

* Boot Camps
  * About
  * Future Boot Camps
  * Map
  * Calendar
  * Past Boot Camps

* Blog
  * Recent Posts
  * All Posts

* About
  * FAQ
  * Sponsors
  * Team
  * Contributing
Merge pull request #197 from jiffyclub/map-show-hide

Ability to turn off "Past boot camps" pins in map
Change the map info window div to take class=info-window instead of id=info-window so we don't end up with a ton of divs with the same id.
Make it so the dropdown caret only highlights when the menu is open.
Moved the About menu over next to Home.
PLoS ad
Merge pull request #209 from gvwilson/master

Blog post about PLoS ad
Merge pull request #205 from jiffyclub/nav-dropdowns

Adding drop downs to Boot Camp, Blog, and About menu items
Blog post about teaching commercially
Merge pull request #211 from gvwilson/master

Blog post about teaching commercially.
Pulling the latest updates to the 3_0 and 4_0 lessons.
Fixes incorrect redirects on images in 4_0 material
Temporary rewrite rule for an old url published for an upcoming bootcamp
Making all the menus, menus
Merge pull request #214 from gvwilson/master

Regularizing menus: the 'Lessons' and 'Badges' items are now also pulldowns (to be consistent).
Blog post by Ross Dickson about Montreal boot camp
Merge pull request #215 from gvwilson/master

Blog post about Montreal boot camp
Adding picture from McGill to FAQ