Refactor experiment views.

Rename functionality with is abstract as mixin classes.
Reorder classes so mixins are before views.
All concrete views inherit from a single base view plus any required
mixins.
Drop use of super in get_context_data

Not really needed - just be explict about what context we want in the
view.
Drop ViewInThisApp class

It doesn't really simplify anything, so let's just drop it.
Mixin refactoring

Remove diamond inheritence.
Merge pull request #2 from tomchristie/view-refactor

View refactor
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appears to be working with all the new updates
appears to be working with all the new updates
got rid of the special case 2 participant sequential game. this provided little value (just participant_1 and participant_2 attributes on the match, which is easy to calculate in a view method if necessary, and player_N_bonus), and requires several classes to be used. then we would need a separate app template. too much overhead, and it's better to be complex. programmers can even use match.participants()[1]
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bug fixing
made fixes to the admin interface for getting start urls
took manage.py and setup.py out of .gitignore