Add 'brief' filter

Simply replaces None with ''

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Add set_node_status_class()

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Add /nodes/ -> NodesController

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Add more stuff to .gitignore

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>