Class OutputImage

The object 'plist' must contain at least the following members:
    plist['output']  - name of output FITS image (for SCI)
    plist['outnx']    - size of X axis for output array
    plist['outny']    - size of Y axis for output array
If 'single=yes', then 'plist' also needs to contain:
    plist['outsingle']
    plist['outsweight']
    plist['outscontext']
If 'blot=yes', then 'plist' also needs:
    plist['data']
    plist['outblot']
    plist['blotnx'],plist['blotny']

If 'build' is set to 'no', then each extension/array must be
in separate FITS objects.  This would also require:
  plist['outdata']    - name of output SCI FITS image
  plist['outweight']  - name of output WHT FITS image
  plist['outcontext'] - name of output CTX FITS image

Optionally, the overall exposure time information can be passed as:
    plist['texptime'] - total exptime for output
    plist['expstart'] - start time of combined exposure
    plist['expend']   - end time of combined exposure

Generate PyFITS objects for each output extension using the file given by 'template' for populating headers.

The arrays will have the size specified by 'shape'.