patch 7.4.2201

Problem:    The sign column disappears when the last sign is deleted.
Solution:   Add the 'signcolumn' option. (Christian Brabandt)

runtime/optwin.vim

@@ -1307,6 +1307,11 @@ call append("$", "\t(local to buffer)")
 call <SID>BinOptionL("bl")
 call append("$", "debug\tset to \"msg\" to see all error messages")
 call append("$", " \tset debug=" . &debug)
+if has("signs")
+  call append("$", "signcolumn\twhether to show the signcolumn")
+  call append("$", "\t(local to window)")
+  call <SID>OptionL("scl")
+endif
 if has("mzscheme")
   call append("$", "mzquantum\tinterval in milliseconds between polls for MzScheme threads")
   call append("$", " \tset mzq=" . &mzq)