OP2/PyOP2 — pull request #61 by wence- (2012-09-22 13:32:15+00:00)
Title: Simplify core.op_arg initialisation

Since the great class hierarchy reordering, the file defining the base
pyop2 classes no longer imports op_lib_core. So we can happily import
base into op_lib_core and use isinstance(arg.data, base.Dat) to
determine if this arg is actually a Dat or a Global when instantiating
the C level op_arg.