Hide exception from users when they try to register twice by using back button
address changes from commets
change to psp redirects, and fix typo
make error page take messages and move try except
Merge branch 'master' of https://github.com/qiime/qiime_web_app into reregisterstop
address more comments
change functions to return 1 or -1
Merge pull request #682 from teravest/reregisterstop

Hide exception from users when they try to register twice