REST related changes before attempting to switch to Jetty/Guice/Jersey/Jackson
switched from jettison to jackson, without much success
Integrated gr.tracer.common and gr.tracer.platform in eu.sqooss.core to overcome issues with rest api and classloader for tracer modules
TRACER REST API is now functional, all operations need to be reviewed
REST related changes before attempting to switch to Jetty/Guice/Jersey/Jackson
merged changes from test branch