Flip arrays - ND support for fliplr and flipud, and replace flipdim with flip. * fliplr.m, flipud.m: add support for N-dimensional arrays by making use of flip(). Added new tests for ND arrays and defaults. * flipdim.m: deprecate in favour of new function flip() which has exactly the same syntax and is part of Matlab since R2014a. * flip.m: new function copied from flipdim. Added tests for ND arrays and defaults. * matrix.txi: replace flipdim DOCSTRINg with flip. * rot90.m, rotdim.m, del2.m: replace flipdim() with flip() * NEWS: note deprecation of flip(), new function flipdim(), and ND support for flipud() and fliplr().