Implemented choice of rotation angle.
Added many code comments.
Added log file which records command-line params.
Better handling of multi-extension input files.
Fixes to merge_headers
minor comment change
Correctly gets reference WCS data from multi-ext img.
Uses get_ref_wcs in regridding.
Datacube output now MEF with useful header.
comment changes
code cleanup
Merge pull request #2 from PBarmby/master

Many changes!