Fix reference frame saved as ICRS instead of FK5
MUSE files and several HST files have EQUINOX=2000.0
only in the primary header, which MPDAF didn't use until now. So, headers produced by wcs.to_header
and saved to files were using RADESYS='ICRS'
instead of 'FK5'
.
This branch adds the optional frame
and equinox
parameters for WCS
, and parse the primary header to find EQUINOX
or RADESYS
and create a WCS in the correct reference frame.