workaround to make Vaadin work with latest Jetty
Work in progress: trying to get sbt compilation working in addition to Maven build

 * copy pasted stuff from Risto's project
 * read a bit sbt tutorial
Added LICENSE file
Revert "workaround to make Vaadin work with latest Jetty"

This reverts commit 7f63edb9410c6747db8f01d6a76ecb502d7e9305.