Rename left/right/up/down relative to active pane to add -of suffix

(left-of/right-of/etc) to remove conflict with left/right meaning
leftmost or rightmost pane. From Ben Boeckel.

cmd-find.c

@@ -102,10 +102,10 @@ const char *cmd_find_pane_table[][2] = {
 	{ "{top-right}", "top-right" },
 	{ "{bottom-left}", "bottom-left" },
 	{ "{bottom-right}", "bottom-right" },
-	{ "{up}", "{up}" },
-	{ "{down}", "{down}" },
-	{ "{left}", "{left}" },
-	{ "{right}", "{right}" },
+	{ "{up-of}", "{up}" },
+	{ "{down-of}", "{down}" },
+	{ "{left-of}", "{left}" },
+	{ "{right-up}", "{right}" },
 	{ NULL, NULL }
 };
 

tmux.1

@@ -496,10 +496,10 @@ The following special tokens are available for the pane index:
 .It Li "{top-right}" Ta "" Ta "The top-right pane"
 .It Li "{bottom-left}" Ta "" Ta "The bottom-left pane"
 .It Li "{bottom-right}" Ta "" Ta "The bottom-right pane"
-.It Li "{up}" Ta "" Ta "The pane above the active pane"
-.It Li "{down}" Ta "" Ta "The pane below the active pane"
-.It Li "{left}" Ta "" Ta "The pane to the left of the active pane"
-.It Li "{right}" Ta "" Ta "The pane to the right of the active pane"
+.It Li "{up-of}" Ta "" Ta "The pane above the active pane"
+.It Li "{down-of}" Ta "" Ta "The pane below the active pane"
+.It Li "{left-of}" Ta "" Ta "The pane to the left of the active pane"
+.It Li "{right-of}" Ta "" Ta "The pane to the right of the active pane"
 .El
 .Pp
 The tokens