Upgrade to Elasticsearch 1.2.1
Upgrade elasticsearch-head to latest version
Fix fabric-hadoop feature
Move the ShutdownTracker to the common-util module since it's utility class and not a core service class.
Expose protocol gateway status via JMX, add more failure condition handle to avoid resource leaks.

- We now shutdown connections if we fail to detect their protocol within a timeout.
- A list of connected and connecting clients can be accessed via JMX.
Add support for optional bundles in profiles in the Fabric API #1850
First attempt at fixing #782
Go through first level dependencies and replace non bundles with matching servicemix bundles, and bundles with features.  Bundle others than the root one are flagged as optionals.
Fix fabric-project-deployer unit test
Fix for https://github.com/fabric8io/fabric8/issues/1901
Fix for https://github.com/fabric8io/fabric8/issues/1901
Added extra variable emptiness check.
Added quickstarts section to the Spring Boot MD.
Added ${project.groupId} and ${project.artifactId} to list of placeholders resolved by the Maven deploy task.
[Maven plugin] Added extra logging.
[Spring Boot] Added placeholders to 'jarUrl' property.
[Maven plugin] Added Javadoc.
[Maven plugin MD] Updated placeholders section.
update docs to minimise the use of heading1 and heading2 so that things fill up the pages a little better in the generated pdf
fix likes/watchers links on gitbook
tidied up the docs so that it generates a better PDF