use cpl_polynmial_* for the fit

git-svn-id: http://svnhq2.hq.eso.org/p2/trunk/Pipelines/cr2re/cr2rep@163184 318c8218-2dab-440d-9263-6f70bac63e5b
fix fit and mask for signal detection. also read all images in sof in preparation for better test data.

git-svn-id: http://svnhq2.hq.eso.org/p2/trunk/Pipelines/cr2re/cr2rep@163253 318c8218-2dab-440d-9263-6f70bac63e5b