PEP 8 import order
Moved function definitions from __init__ to time.py module.  Corrected all modules for pep8 import compliance.  Removed import lines from inside functions.  Cleaned up absolute imports.
Updated tests to new import pattern, moved a julian_day test to test_julian_day
Fixed failing test.
Fixed interface with sunpy.time module.  Made references to sunpy.time consistent.  Cleaned up imports to match PEP 8.