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/prefs/private/saveprefs.m
+++ b/scripts/prefs/private/saveprefs.m
@@ -32,7 +32,7 @@
 endfunction
 
 
-%% Testing these functions will require some care to avoid wiping out
-%% existing (or creating unwanted) preferences for the user running the
-%% tests.
+## Testing these functions will require some care to avoid wiping out
+## existing (or creating unwanted) preferences for the user running the
+## tests.