Display Version

Rename POM version to 0.9.0
Add maven plugins to substitute two variables from POM into layoutHeader. Namely ENVIRONMENT and APP_VERSION. The version will be displayed in the header and the environment is used to to ensure that in PROD the UI displaying the baked in users is not displayed.

To make the version work locally, ensure that when running jetty locally it's invoked with jetty:run-exploded rather than jetty:run.