Ephemerides Update

This update is the first update that calculates pixel positions on the master image for the ephemerides. It also adds them to the database. The results still need to be verified.

ephpm/ephem.py:
    - get_header_info: Added new header keywords to the dictionary.
    - Added the calc_ephem function
    - Added the calc_targ function
    - Added calls to the above functions to the main_ephem module.

ephem/build_master_table.py:
    - Refactored the way the number of results in a query is counted.