Add clf() to all plot demos. * axis.m, compass.m, contour3.m, contourf.m, cylinder.m, ellipsoid.m, errorbar.m, ezcontour.m, ezcontourf.m, ezmesh.m, ezmeshc.m, ezplot.m, ezplot3.m, ezpolar.m, ezsurf.m, ezsurfc.m, feather.m, fplot.m, loglogerr.m, pcolor.m, pie.m, pie3.m, plot3.m, plotmatrix.m, quiver.m, quiver3.m, refreshdata.m, ribbon.m, rose.m, scatter3.m, semilogx.m, semilogxerr.m, semilogy.m, semilogyerr.m, shading.m, sombrero.m, stairs.m, stem.m, stem3.m, surf.m, surfc.m, surfl.m, surfnorm.m, trimesh.m, triplot.m, trisurf.m, uimenu.m: Add clf() to the beginning of each demo to ensure pre-existing graphics objects don't interfere with the demo.

--- a/scripts/plot/compass.m
+++ b/scripts/plot/compass.m
@@ -112,6 +112,7 @@
 
 
 %!demo
+%! clf
 %! randn_9x1_data = [-2.555884; 0.394974; -0.191871; -1.147024; 1.355425; -0.437335; -0.014370; -0.941312; 1.240300];
 %! randn_1x9_data = [1.42934, -1.10821, -1.70404, 0.63357, -0.68337, -1.19771, -0.96502, -1.12810, 0.22457];
 %! a = toeplitz ([1;randn_9x1_data], [1,randn_1x9_data]);