Rebase keystone.conf to Grizzly.

Actually uncomment sql.idle_timeout. The following options where dropped
from keystone.conf: public_host, admin_host, compute_host, min_pool_size,
max_pool_size, pool_timeout. Use default compute_port (8774), the nova
cookbook does the same. Provide public_endpoint/admin_endpoint for the
v3 API.
Merge pull request #84 from saschpe/release/pebbles/master-keystoneconf-grizzly

Rebase keystone.conf to Grizzly.