Refactoring discussion routes to allow for more dynamic JSON calls

I've done away with putting query params in the URL.
This was creating a bit of a mess.

We can now dynamically load in more/less comments dependant on user signals (i.e. have you clicked on the "Show comments" button before) and save on initial load size when calling a discussion i.e. When it's JSON it's 10, when it's on the page it's 50. We will be looking at upping this for people who hgave clicked on "show comments" repeatedly.

![Routes...](http://2.bp.blogspot.com/-qJaJz9hSV6E/UoszURHip1I/AAAAAAAAX2g/TQ66x6qcMqk/s1600/tumblr_m91etz18X01rt0g8wo1_500.gif)