maven: Use a local file based repo

Instead of asking the user to add things to the ~/.m2 repo, add a local file
based repo created with

mvn install:install-file -Dfile=lib/spics.jsf.jar -DgroupId=spics -DartifactId=spics-jsf -Dversion=1 -Dpackaging=jar -Dmaven.repo.local=./repo