Bug 1036928 - Allow to set longer time estimages as 60 minutes

Closed the previous pull- working only on this branch now.
Here is a link to a blog post that makes a suggestion about how one might address this validation issue: http://twigstechtips.blogspot.ca/2011/10/django-dynamic-checkboxselect-options.html

I'm not saying that is the exact solution we need, but at least it explains where the code if that is doing the validation.