upgrade foreman to rails 3.2.13

This commit updates from rails 3.0.x to 3.2.x, main changes include:

* Asset pipline support
* cleanup of existing assets (javascript, css, images)

Users who uses foreman in production, make sure that you now compile
your assets, e.g

rake assets:precompile

Paired-with: Joseph Mitchell Magen <jmagen@redhat.com>
Paired-with: Ohad Levy <ohadlevy@gmail.com>

Signed-off-by: Ohad Levy <ohadlevy@gmail.com>
fixes #2360 loading parameters on host edit form when hostgroup or environment is changed