Migrate to maven-publish plugin from maven plugin for publishing
artifacts.

Add source jar to published artifacts.
Bring README inline with latest version changes.
Add WebappServerBuilder for building REST + static content in one server.
Bump version to 1.2.2 with the addtion of WebappServerBuilder for
JAX-RS + static content hosting.
Bump version to 1.2.2 in README
Add javadoc for WebappServerBuilder
README and javadoc improvements
Configure JaCoCo test report to generate line numbers.