issue17:fix led model memory bug; issue19:header time is not utc bug; issue18:header data-obs\darktime\exposure time fix by shaoli's chart;add new star catalog:C6_50sqdeg_ns.py

1. add project_cycle, run_counter to config file. Modified obsid to reflect this change. Applied the same obsid to ".cat" and ".log" files.
2. limiting mags are now based on the field types (WIDE or DEEP) which can be specified in pointing list.
3. Stars are now drawn directly as PSF.
4. Reorgnaized lists of filter types in Instrument._util.

rotate e1, e2.
remove the rotation parameter in Galaxy class (not used before).
modeling of ellpiticity rotation should be implemented in Catalog.py