Release candidate for 3.0

R3.0rc (2015-12-14)

User-interface changes

New entry expiration in job_params.cfg (#472):

[source_extraction]
expiration = 10  ; number of forced fits performed after a blind fit

Features / Enhancements

• Added support for AARTFAAC format images (#444, #452).
• Expiration of forced-fit monitoring at locations with no recent blind
  detections (#472).
• Caching of additional variability metrics (varmetric table) to improve
  interactive queries via the 'Banana' web-interface (#469).

Refactoring / Infrastructure changes

• Started integrating SQLAlchemy as a future replacement for home-grown
  database-ORM code (#362).
• Migrate from PyFITS to astropy.io.fits (#355).
• Removed unused 'Celery' code (#433).