OF-2196: Add dependency for JAXB-API in Java 11

OF-2196: Add dependency for JAXB-API in Java 11

OF-2196: Add dependency for JAXB-API in Java 11

OF-2196: Add dependency for JAXB-API in Java 11

OF-2196: Add dependency for JAXB-API in Java 11

OF-2195: Add Git SHA to version string in Admin header

OF-2195: Add Git SHA to version string in Admin header

OF-2195: Add Git SHA to version string in Admin header

OF-2195: Add Git SHA to version string in Admin header

OF-2195: Add Git SHA to version string in Admin header

Better cross-platform integration tests (#1539)
* Add script launch structure with getopts, add hosts file editing

* Stop openfire when tests end

* Add alternate host/credential options

* Add usage and error handling to test runner script

* Improve hosts file editing (and prevent it in Travis)

* Swap Smack clone for Smack from maven, tidy all the things

* Move openfire-demoboot.xml to Openfire repo

Solves a TODO. Could now run without internet connectivity

* Add logic to deal with differing versions of Smack

* Fix for Java11

* Re-enable unbroken tests

* Re-disable tests that fail in Travis

Improve Dockerfile
* Include maven by default rather than installing
* Separate run steps for local caching

OF-2111: Read and write MUC maxbatchsize to the same setting

OF-2111: Read and write MUC maxbatchsize to the same setting

Exclude files not relevant to the docker image
Improves caching of build stages