Worked on trail pics a bit.

Wrote up a document explaining how we determine trail pics.
Merge branch 'master' of github.com:guardian/frontend into trail-pics
ignore breking codes
Fix test group
not using trailblock-show-more module anymore
Articles can load commercial components

Included is a simple commercial component loader, packaged and managed as part of our applcation but designed provide an sensible interface for
OAS/DFP to load our own adverts (based on AMD).

```
// load the 'travel' component
require('modules/commercial/loader', function (CommercialComponent) {
    new CommercialComponent(document, { config: guardian.config }).load('travel', document.getElementById('ad-slot'));
})
```
XHR host name is now environmentally friendly
don't hide image if inlined
Added more basic discussion tracking and fixed a few bugs
starting to pull in show more ajax style
Adding Bonzo's static methods to $
Merge branch 'master' of https://github.com/guardian/frontend into discussion-tracking
Merge branch 'add-bonzo-static-methods-to-$' of https://github.com/guardian/frontend into discussion-tracking
pull in collection show more over ajax
OASTOKEN replacement
Semi-colon
handle changing viewport size
popular works, again
WIP
There shouldn't be a main industry for general jobs