More consistency with how -B0 is used (#4293)

* Let -B0 only imply x-y map, not z-axis

* Update gmt_init.c

Let 2D vs 3D decide what -B0 means and the type of title.

* Update filler.sh

* Update QR.ps

Author: PaulWessel

src/gmt_init.c

@@ -4263,7 +4263,8 @@ GMT_LOCAL int gmtinit_parse5_B_option (struct GMT_CTRL *GMT, char *in) {
 		if (no == GMT_Z) GMT->current.map.frame.drawz = true;
 		if (!text[0]) continue;	 	/* Skip any empty format string */
 		if (text[0] == '0' && !text[1]) {	 /* Understand format '0' to mean "no annotation, ticks, or gridlines" */
-			GMT->current.map.frame.draw = GMT->current.map.frame.drawz = true;	/* But we do wish to draw the frame */
+			GMT->current.map.frame.draw = true;	/* But we do wish to draw the frame */
+			if (GMT->common.J.zactive) GMT->current.map.frame.drawz = true;	/* Also brings z-axis into contention */
 			GMT->current.setting.map_frame_type = GMT_IS_PLAIN;	/* Since checkerboard without intervals look stupid */
 			continue;
 		}

test/psxyz/QR.ps

@@ -8,10 +8,9 @@ cat << EOF > t.txt
 4 4 0
 EOF
 
-gmt psxyz -R0/5/0/5/0/1 -JX3i -JZ1i -P -K -p170/35 -Bwesn t.txt -Gred -W2p -L+yb > $ps
-gmt psxyz -R -J -JZ -O -K -Bwesn -p t.txt -Gred -W2p -L+yt -X3.5i >> $ps
-gmt psxyz -R -J -JZ -O -K -Bwesn -p t.txt -Ggreen -W2p -L+xl -X-3.5i -Y3.2i >> $ps
-gmt psxyz -R -J -JZ -O -K -Bwesn -p t.txt -Ggreen -W2p -L+xr -X3.5i >> $ps
-gmt psxyz -R -J -JZ -O -K -Bwesn -p t.txt -Gorange -W2p -L+y4 -X-3.5i -Y3.2i >> $ps
-gmt psxyz -R -J -JZ -O -K -Bwesn -p t.txt -Gorange -W0.5p,white -L+x4.5+p2p -X3.5i >> $ps
-gmt psxy -R0/5/0/5 -J -O -T >> $ps
+gmt psxyz -R0/5/0/5/0/1 -JX3i -P -K -p170/35 -B0 t.txt -Gred -W2p -L+yb > $ps
+gmt psxyz -R -J -O -K -B0 -p t.txt -Gred -W2p -L+yt -X3.5i >> $ps
+gmt psxyz -R -J -O -K -B0 -p t.txt -Ggreen -W2p -L+xl -X-3.5i -Y3.2i >> $ps
+gmt psxyz -R -J -O -K -B0 -p t.txt -Ggreen -W2p -L+xr -X3.5i >> $ps
+gmt psxyz -R -J -O -K -B0 -p t.txt -Gorange -W2p -L+y4 -X-3.5i -Y3.2i >> $ps
+gmt psxyz -R -J -O -B0 -p t.txt -Gorange -W0.5p,white -L+x4.5+p2p -X3.5i >> $ps