Various fixes for tests in scripts/plot plot/cla.m: Use figure number 1232. plot/clf.m: Split test into two. plot/findall.m: Check only for graphic objects in figure 1232. plot/findall.m: Ditto. plot/gcf.m: Simplify test. plot/line.m: Check against default values now. plot/whitebg.m: Restore default values after tests.

--- a/scripts/plot/gcf.m
+++ b/scripts/plot/gcf.m
@@ -57,9 +57,7 @@
 %!test
 %! hf = figure (1232, "visible", "off");
 %! unwind_protect  
-%!   line;
-%!   clf;
-%!   assert (isempty (get (gcf, "children")));
+%!   assert (gcf, 1232);
 %! unwind_protect_cleanup
 %!   close (hf);
 %! end_unwind_protect