added basic info endpoint
Remove `--task_rate_limit` flag from README
Docker JSON blob example
fixes #397 Docker image field is lost if  field is not set
fixes #394 add leader and frameworkId to /v2/info
fixes #395 Allow Marathon users to specify what user to run tasks as
making the startup port for tomcat dynamic
Simplified HealthCheckManager.update interface
Merge pull request #399 from kensipe/tomcat_example

making the startup port for tomcat dynamic
Moved health check proto logic to TaskBuilder

- other minor cleanup items identified in review
Merge branch 'master' into 0.7.0-preview

Conflicts:
	src/main/scala/mesosphere/mesos/TaskBuilder.scala