Mostly fixing typos...
Fixed extension building to build app first.  Closes #63
Updated spark for newer interfaces (builds)
Attempt at ivy resolution of Spark dependencies.
Improved paramter message.
Modified default arguments.
Updated serialization for int aggregates.
Merge branch 'master' into spark
Spark assembly on classpath.
Spark dependency fetching in ant, some other restructuring.
Ignoring eclipse classpath changes...
Documentation changes.  Argument simplification
Removed unused annotation.