Add target to generate workflow documentation

This currently needs to be called manually.
Don't use the redirect trick to populate playoff index context

We can just do this directly from the page and save a round trip.

task #292: Report to rank teams in a division by performance score 
http://github.com/jpschewe/fll-sw/issues/issue/292
Populate admin index context directly

Saves a round trip
Refactor checking if tables are assigned

This allows it to be checked easily elsewhere.

task #19: Update documentation for playoffs 
http://github.com/jpschewe/fll-sw/issues/issue/19
Make it clear to the user that tables should be assigned before doing
scoresheet generation

task #19: Update documentation for playoffs 
http://github.com/jpschewe/fll-sw/issues/issue/19
Store variables in page context rather than session context

Shorten the lifetime so that we don't end up leaving junk in the session
and confusing other pages.
Update changes
Merge branch 'ticket.19.check-tables-assigned'

Fixes #19