Introduce competition stages for multi-stage comps (World Cup)

Stages are one of:

League
Groups
Knockout

Each of these will be displayed differently - full league table, group
tables or multi-round tournament knockout spider.
Add and test extra data on CompetitionStage classes

Now contains the data needed to render stages on the frontend.
Worldcup wallchart with test data
Merge remote-tracking branch 'origin/football-groups' into competition-stages-wallchart
Combine backend and frontend work

Now have real data driving the world cup wallchart.
Add detail to the wallchart implementation

Matches are now displayed more completely - incldues score for live
matches / results, as well as match comments.

Also supports league stages
Remove old template file
Force compatition agents to use latest startDate

This means they'll only have data for the current season. It might be
nice to keep the "earliest start date" as another property so we can
still have data for previous seasons. Alternatively, add "most recent
start date" and use that to provide a "this season's matches" lazy
val.
Order group stages in wallchart
Add tournament group match lists to wallchart
Stlying for wallchart on desktop and groups
Styling in merge fixed
Merge branch 'competition-stages-wallchart-single-season' into competition-stages-wallchart
Correct styling to group stages
Add embeddable wallchart
Merge remote-tracking branch 'origin/competition-stages-wallchart' into competition-stages-wallchart
Add wallchart ordering for WC2014

Knockout has been generalised to:
* KnockoutSpider - for knockouts with ordering info for spidering
* KnockoutList - for all other knockouts

The World Cup 2014 wallchart is the former, but KnockoutList lets us
neatly support an overview for all other tournaments (with trivial
extra code)
Tidy up embed JS for same domain
Added playoff and dayofweek to matches
Show knockouts on other competititons