Adds build support using tycho and maven

This changeset adds the following new projects:
 * `org.eclipse.babel.tapiji.tools.parent`: Encapsulates the root pom file for maven and all commom pom settings
 * `org.eclipse.babel.tapiji.tools.target`: Specifies the target platform used for building the babel tool suite

Moreover, each project has been enhanced with a pom build definition that inherits from the pom located in `org.eclipse.babel.tapiji.tools.parent`.