Added a Composer file with license

With this commit we add the composer.json and lock file together
with a license file indicating that this project is under the
MIT license (discussed with @akrabat to be sure).

In addition to the above I have prevented the .git folder in the
vendor folder from being committed.

The vendor folder itself will be submitted in a separate commit
to make it easier for a code reviewer to see which changes are
the onces actually needing a review.
Replace all vendors with composer loaded vendors

The vendors folder was manually maintained and with the previous
commit we added support for composer to maintain the vendors for
this project.

With this commit we update the vendor folder to contain all the
generated dependencies by composer so that the correct versions
are deployed.
Rewire application to use composer

The composer no longer requires on custom autoloaders. Composer
takes care of all these necessities.

In this commit I have removed all existing autoloading code and
added the autoloading of composer.
Add Bootstrap 3.1.1
Add FontAwesome 4.1.0
Update jQuery to 2.1.1
Switch to using Bootstrap

- Now actually responsive!
- Adds sidebar
  - Login, takes you back to the same page
  - Splits to have event info on top of page, login below page
  - Combell logo disappears on mobile, as it's directly above the footer which also contains it
- Added a link to github in the footer (left)
- Nicer pager
- Clearer (actionable) "I will be attending"/"I attended" text+buttons
- Short URLs now have a "Copy to Clipboard" UI
  - uses flash but:
  - is hidden on mobile/tablet
  - will highlight the text in the input when focused, or clicked without flash
- Comments have a new interface
  - Supports gravatar
  - Comment shown above author/date/via
  - via is hidden on mobile
  - When ratings are shown they are also responsive:
    - Horizontal/on-top for desktop
    - Vertical/left for small/tablet
    - Vertical/on-top for mobile
- Twig will check for local images before linking to the old joind.in site
Strip down bootstrap to the essentials
Make the key responsive
Disable zoom
Add gulp to minify/concat JS/CSS
Add `watch` task
Revert "Disable zoom"

This reverts commit 85c73a25d3713384caf6dc4693c61f3dbbd812b0.

Conflicts:
	app/templates/layout.html.twig
Add a header to state files are generated
Fix bug in FF where it scrolls to the bottom
Switch to PNG images
Customize FontAwesome
Rework comments to use less space
Fix search form to point to `/search/events`
Fix pager UI when there is no next page