High: Introduces the docker agent to manage docker containers in an HA environment
Low: docker: fixes run_opts short description
Fix: docker:  properly handle images with tags
Low: docker: increase recommended action timeouts
High: docker: force_kill option for immediately killing docker container on stop
Low: docker: make use of exit reason string
High: docker: Introducing the 'reuse' container option

By default containers started with the docker OCF agent are dynamically
created on start and removed after stop. By using the 'reuse' option,
containers will never be destroyed after stop, allowing the same container
to be reused.
Low: docker: use docker inspect --format instead of grep pattern
High: docker: default container name to resource instance name

originally the default container name was the resource instance
name prefixed with 'HA-'. This is confusing and unncessary. Now
the container name defaults directly to the resource instance name
with no prefix.
Merge pull request #370 from davidvossel/docker_agent

High: Introduces the docker agent to manage docker containers in an HA environment