Add auto-logging to ccdproc

+ Auto-logging occurs in the *metadata* using the full function name as the key even though that isn't FITS-compliant.
+ FITS pseudo-compliance is handled by ``CCDData.to_hdu`` because that is the point at which which compliance arises.
    + Pseudo-compliance means that the keyword is shortened to 8 characters or less.
    + The value can have any length, accommodated by ``astropy.io.fits`` with the CONTINUE convention, which is not FITS-compliant but is close enough.