patch 8.1.1072: extending sign and foldcolumn below the text is confusing

Problem:    Extending sign and foldcolumn below the text is confusing.
Solution:   Let the sign and foldcolumn stop at the last text line, just like
            the line number column.  Also stop the command line window leader.
            (Christian Brabandt, closes #3964)
diff --git a/src/testdir/dumps/Test_diff_15.dump b/src/testdir/dumps/Test_diff_15.dump
index 0eb1813..3b880eb 100644
--- a/src/testdir/dumps/Test_diff_15.dump
+++ b/src/testdir/dumps/Test_diff_15.dump
@@ -6,15 +6,15 @@
 | +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0@2|r|e|t|u|r|n| |0|;| @22||+1&&| +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0@5|r|e|t|u|r|n| |0|;| @19
 | +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1| +0#0000000#5fd7ff255@2|}| @30
 | +0#0000e05#a8a8a8255@1|}+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|}+0#0000000#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
-| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|~+0#4040ff13&| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
 |X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
 |:+0&&|s|e|t| |d|i|f@1|o|p|t|&|v|i|m| |d|i|f@1|o|p|t|+|=|f|i|l@1|e|r| |d|i|f@1|o|p|t|+|=|i|w|h|i|t|e| @26