graphx merge for scala 2.9

[Koert Kuipers]

since we are still on scala 2.9.x and trunk migrated to 2.10.x i hope
graphx will get merged into the 0.8.x series at some point, and not just
0.9.x (which is now scala 2.10), since that would make it hard for us to
use in the near future.
best, koert