bootcamps: Add 'restricted' metadata to restricted bootcamps

I may have missed some, since I only tagged bootcamps found with:

  $ grep -i restrict bootcamps/*.html
compile.py: Parse the new 'restricted' metadata

The value is just a string, so use 'true' or '' for True/False, taking
advantage of the fact that bool('') == False.
bootcamps/index.html: Different markers for restricted boot camps

I made the marker legend a paragraph, since I was concerned about a
wide table if we went with:

  ? Future Open Boot Camps  ? Future Restricted Boot Camps  ...

and a grid of future/past open/restricted seemed too confusing ;).
The paragraph should flow reasonably well, even on narrow screens.

I also removed the in-tree versions of the old pins, since I haven't
checked the legality of that [1], and if we can't get to
chart.apis.google.com to fetch the markers, we're probably not going
to get the map from maps.googleapis.com either ;).

If the number of markers continues to grow, it may be worth bundling
them into some sort of structure to avoid duplicate entries in the
JavaScript header and the in-body legend, but I don't think we're
quite there yet.

[1]: https://github.com/swcarpentry/website/pull/192#issuecomment-11928689
bootcamps/index.html: Label restricted bootcamps in lists

I just append '(restricted)' to the venue, but we could add a new
table column.  We could also add a 'restricted' class if folks want to
do some CSS styling.  Hopefully these restricted boot camps are rare
enough that such special handling isn't worth the effort ;).
Removed registration form (temporary, until registration opens).
Merge pull request #317 from amyrbrown/ua-registration

Removed registration form on Arizona camp page (temporary, until registration opens).
Showing registration status for boot camps on index page
Merge pull request #199 from wking/restricted-boot-camps

Indicate whether boot camp is open or closed on Boot Camp page
* Merging Trevor King's modifications to boot camp compilation to show open/restricted status.
* Adding optional metadata 'registration' to boot camp pages to show if they are open or restricted.  If metadata not present, boot camp registration hasn't started yet.
* Changing format of boot camp index page accordingly.
This should fix issue #295. It doesn't matter where in the template the pageclass identifiers are so long as they're there.  They shouldn't come before the inclusion of the base template because then they are rendered before the doctype declaration, which confuses IE.
Moving the pageclass declaration so as not to confuse IE (see #295)
Forgot to update the blog index template as well
Advertising the bootcamp for WiSE
Merge branch 'master' of github.com:gvwilson/website into blog
Merge branch 'master' of github.com:swcarpentry/website into blog
Updating submodule reference to latest
Merge pull request #321 from gvwilson/master

Merging change to submodule. Updates for #295.
Merge pull request #295 from iguananaut/issue-295

Menu bar on web site fails on Internet Explorer
Merge pull request #322 from gvwilson/pageclass

Moving the pageclass declaration so as not to confuse IE (see #295)
Merge branch 'master' of github.com:swcarpentry/website into blog