add config option to disable text scrolling in header window

doc/config

@@ -147,6 +147,8 @@
 #
 #statusbar_visibility = "yes"
 #
+#header_text_scrolling = "yes"
+#
 #fancy_scrolling = "yes"
 #
 #cyclic_scrolling = "no"

doc/ncmpcpp.1

@@ -120,6 +120,9 @@ One of colors used in Song info, Tiny tag editor and Search engine.
 .B colors_enabled = yes/no
 No need to describe it, huh?
 .TP 
+.B header_text_scrolling = yes/no
+If enabled, text in header window will scroll if its length is longer then actual screen width, otherwise it won't.
+.TP 
 .B fancy_scrolling = yes/no
 If enabled, content of other columns will be updated immediately while scrolling, otherwise only after you stop scrolling.
 .TP