fix typo :)
introduce locale (as sites subdir and optional param), and...

* use Sinatra 1.3.6
* add short stack trace to error log
* various refactorings
* put Deck file server ahead of Sinatra in middleware chain (using Rack::Cascade)
use subdomain, param, or environment variable to specify locale
TOC now works with locale
Merge pull request #313 from alexch/locale

Locale
Comment about comments

Because we had a lot of issues with folks leaving this line commented
out after editing, I think it’s worth mentioning that # at the start of
the line means it’s a comment.
clean up syntax error messages
use rspec double() instead of deprecated mock()
bundle update (removing x86-mingw32 platform)
flag icons in page header
raw port from codelikethis
simple navigation and summary for Learn To Code
De-jargon-ify MVC explanation.

Prefer stating true things to metaphors. Metaphors won't help later, and
facts can at least give them a vocabulary and concepts to start putting
together.
split out separate 'rails architecture' page
process 'goal' text as markdown; improve stepfile docs
code and routing to show a markdown page as slides
Merge pull request #321 from alexch/master

flag icons in page header
fix test
Merge pull request #298 from railsbridge/never-speak-mvc

De-jargon-ify MVC explanation.
Merge pull request #322 from alexch/learn_to_code

Learn to code