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/sparse/gplot.m	Mon Feb 23 16:42:25 2015 +0000
+++ b/scripts/sparse/gplot.m	Mon Feb 23 14:54:39 2015 -0800
@@ -79,6 +79,6 @@
 %! set (get (gca, ("children")), "markersize", 12);
 %! title ("gplot() of Binary Tree Adjacency matrix");
 
-%% Mark graphical function as tested by demo block
+## Mark graphical function as tested by demo block
 %!assert (1)