Handle parenthesis in spreadsheet column names

Actually mask out anything that's not a-z, A-Z, 0-9 or '_'.

Fixes #176

task #176: Trouble uploading teams [sf#141] 
http://github.com/jpschewe/fll-sw/issues/issue/176
Merge branch 'ticket.176.bad-teams-spreadsheet'
Put subjective app information on the admin index page

Fixes #209
Merge remote-tracking branch 'origin/master'