Themes

- Added the new color.blocking to each theme.  In most cases it is the
  same as color.blocked, with something slightly 'bolder' about it, but
  in the more quirky ones it is the same.  These need tweaking.

doc/rc/dark-256.theme

@@ -70,6 +70,7 @@ color.pri.M=color250
 color.pri.L=color245
 color.tagged=rgb031
 color.blocked=white on color8
+color.blocking=white on color15
 color.project.none=
 color.tag.none=
 color.alternate=on color233