Cleanup. Remove deprecated FITSView::getImageData. Fix typo.
FITSView::getImageData() was deprecated in commit 1785e50c, but there were still many references to it in the code. This removes that call, and makes the necessary code changes to use the newer FITSView::imageData() call instead.
Also fixes a minor typo sovler-->solver which was a part of the astrometryparser interface and thus existed in several files.
There should be no functional changes.