Add the jquery tablesorter plugin from http://tablesorter.com
Add small gif icons that will be used to indicate the table can be sorted
In the package view, make the committers' table sortable by its column
Adjust the CSS to make the committers' table prettier when sorted

Fixes https://github.com/fedora-infra/pkgdb2/issues/67
Merge pull request #70 from fedora-infra/order_users

Order users