keystone: remove duplicate paste.ini config

Rename paste.ini keystone-paste.ini as expected by keystone.
keystone: ensure keystone-paste.ini is loaded
nova: load nbd kernel module

Nova uses qemu-nbd for file insertion and does not load the kernel
module automatically.
nova: use /etc/modules for Ubuntu 12.04 comptability
Merge pull request #553 from blueboxgroup/fix-nova-nbd-module

nova: load nbd kernel module
Merge pull request #550 from blueboxgroup/keystone-paste-ini

keystone: remove duplicate paste.ini config
nova: fix deprecated quantum network config