url_validator raises InvalidUrl error when nil is given

This fixes "cryptic" errors that we were getting from Airbrake. If
anything goes wrong with #heuristic_parse it's perfectly fine to raise
InvalidUrl error and handle it.

```
Addressable::URI.heuristic_parse(nil) #=> nil
nil.path #=> NoMethodError
```
kill a bug in IE (that should be a bug everywhere...)
Merge pull request #819 from lonelyplanet/chee/bug/internet-explorer-swipe

kill a bug in IE (that should be a bug everywhere...)
Merge pull request #814 from lonelyplanet/url_validator_fix

url_validator raises InvalidUrl error when nil is given
Fix gallery tracking
Add test for Gallery.js
Center lightbox with css instead of javascript and make it kinda responsive
Remove the test for the lightbox centering. Now, the centering is done with css
Merge pull request #783 from lonelyplanet/jesus/bug_lightbox

Center lightbox with css instead of javascript and make it kinda responsive
Suppress tynt on styleguide.
Merge pull request #822 from lonelyplanet/remy-styleguide_tynt

Suppress tynt on styleguide.
Merge pull request #821 from lonelyplanet/if-fix-gallery-tracking

Fix gallery tracking
Remove the .json extension when generating page state
Merge pull request #826 from lonelyplanet/remy-controller_json

Remove the .json extension when generating page state
add route for custom layouts (LP India, etc)
changed variable names, cleaned up to pass tests
added 'defaults' to layout support hashes
 formatted routes file. added config hash for old routes
moved js-nav--primary outside of if statement for injecting custom menus
Add helper function and tests to clean up layout_support