8.17.18 ctype2sbas(self):

ctype2sbas $<$ MamboMBFits: $<$ MamboMBFits.py

    DES: Converts the infos about the Astronomical basis frame from MB-FITS
    keywords (CTYPEj, EQUINOX...) to a SBAS value (+ epoch). The results
    are stored and returned in a dictionary.