Build with CBI

- Build now uses Maven/Tycho to produce artifacts
- p2 repository can be found in:
    repository/target/
- sapphire-samples zip can be found in:
    samples/target/
- To build with bree-libs enable the profile:
    -Pbree-libs
- To sign the build using Eclipse infrastructure:
    -Peclipse-sign

Signed-off-by: Thanh Ha <thanh.ha@eclipse.org>