maint: Clean up m-files to follow Octave coding conventions. Try to trim long lines to < 80 chars. Use '##' for single line comments. Use '(...)' around tests for if/elseif/switch/while. Abut cell indexing operator '{' next to variable. Abut array indexing operator '(' next to variable. Use space between negation operator '!' and following expression. Use two newlines between endfunction and start of %!test or %!demo code. Remove unnecessary parens grouping between short-circuit operators. Remove stray extra spaces (typos) between variables and assignment operators. Remove stray extra spaces from ends of lines.

--- a/scripts/general/shiftdim.m
+++ b/scripts/general/shiftdim.m
@@ -44,7 +44,7 @@
 ##    @result{} ns = 1
 ## @end group
 ## @end example
-## @seealso {reshape, permute, ipermute, circshift, squeeze}
+## @seealso{reshape, permute, ipermute, circshift, squeeze}
 ## @end deftypefn
 
 function [y, ns]  = shiftdim (x, n)
@@ -93,7 +93,7 @@
 
 %!assert (size (shiftdim (rand (0, 1, 2))), [0 1 2])
 
-%% Test input validation
+## Test input validation
 %!error (shiftdim ())
 %!error (shiftdim (1,2,3))
 %!error (shiftdim (1, ones (2)))