Implement Operator 'nbytes' property.
Add context manager 'setting'.
Fix __str__ and __repr__ for non-initialized operators.
Implement DeletedOperator, and an nbytes counter-based garbage collection trigger.
Implement ProxyOperator.
Convert angle(s) to proper dtype using asarray.
Update MANIFEST.in file.
Fix ReshapeOperator's transpose.
Make update_output flag a regular operator flag (was inplace_reduction).
Allow generators in composite operators.