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/validateattributes.m
+++ b/scripts/general/validateattributes.m
@@ -338,6 +338,7 @@
   endif
 endfunction
 
+
 %!error <double> validateattributes (rand (5), {"uint8"}, {})
 %!error <single> validateattributes (uint8 (rand (5)), {"float"}, {})
 %!error <2d> validateattributes (rand (5, 5, 5), {}, {"2d"})