Fix usermod error UID 0 already exists.

This bug prevented rancher/server from starting when a non-vboxfs
directory was used as the mount point for /var/lib/mysql. In the
case of docker-machine/boot2docker any directory outside of /Users
on a Mac or non rancher/server container volumes from meet this
criteria. VBoxFS mounts do not allow changing UID/GID or permissions
of the directory. To address we change the UID of the MySQL user
to the directory owner UID.

Ignore docker inspect on state run

Fix idempotency on sed

ignore -- when starting container.

Add capability to use agent from private registry

Add bindmounting in certificate for ldap ssl/tls

[WIP] Add support to download and run local agents

To support networks that may not have access to CDN the agents
are now downloaded into the rancher/server container. They are
compressed and accessed through the CATTLE_ settings. The default
behavior will now be to use the local agents. If a user wants to
leverage the CDN versions a `-e USE_LOCAL_AGENTS=false` must be
passed when starting the container.

MySQL bind mount support