updates UI to bootstrap v2

fixes #1236 - multiple actions modal

fixes #815 - Redirect to login page when editing multiple hosts

this patch converts the mulitple selections to be pure javascript,
removing the buggy AJAX implementation.

Fixes #258: Change Environment for multiple hosts.

Fixes #179 - allow mass assignment of parameters and host groups.
Greatly inspired by Ashay Humane <ashay.humane@gmail.com> at 5c2e395c