Removed superfluous import from engine.py

darcs-hash:20090130163542-58103-ff9c548ecb486081ab365dd4a19f12f0133dfe70
Put all pypjua.core imports in engine.py on one line

darcs-hash:20090130163630-58103-788ce48c61d1a4fcb6f4c3725d97166d3685518f