Overhaul image, imagesc to use newplot and support low-level invocation form. * scripts/image/image.m: New variable do_new indicates high-level calling form. For high-level invocation, call newplot before __img__. Correct linearity check if vectors are reversed (high-to-low values). Only apply image properties to axes if doing a high-level invocation. * scripts/image/imagesc.m: New variable do_new indicates high-level calling form. Delete subfunction __imagesc__ and incorporate minimal amount of code into imagesc. Only apply climits for high-level invocation.

%!function r = f1 ()
%!  ls = svd (1);
%!  r = eval ("ls -1;");
%!endfunction
%!function r = f2 ()
%!  [u,ls,v] = svd (1);
%!  r = eval ("ls -1;");
%!endfunction
%!function r = f3 (ls)
%!  r = eval ("ls -1;");
%!endfunction

%!assert (f1 (), 0);
%!assert (f2 (), 0);
%!assert (ischar (f3 ()), true);
%!assert (f3 (1), 0);