Extend the #[] style syntax and use that together with previous format

changes to allow the status line to be entirely configured with a single
option.

Now that it is possible to configure their content, enable the existing
code that lets the status line be multiple lines in height. The status
option can now take a value of 2, 3, 4 or 5 (as well as the previous on
or off) to configure more than one line. The new status-format array
option configures the format of each line, the default just references
the existing status-* options, although some of the more obscure status
options may be eliminated in time.

Additions to the #[] syntax are: "align" to specify alignment (left,
centre, right), "list" for the window list and "range" to configure
ranges of text for the mouse bindings.

The "align" keyword can also be used to specify alignment of entries in
tree mode and the pane status lines.

tmux.1

@@ -251,6 +251,7 @@ client.
 .It !
 Break the current pane out of the window.
 .It \&"
+.\" "
 Split the current pane into two, top and bottom.
 .It #
 List all paste buffers.
@@ -2838,9 +2839,22 @@ is on.
 The values are the same as those for
 .Ic activity-action .
 .It Xo Ic status
-.Op Ic on | off
+.Op Ic off | on | 2 | 3 | 4 | 5
 .Xc
-Show or hide the status line.
+Show or hide the status line or specify its size.
+Using
+.Ic on
+gives a status line one row in height;
+.Ic 2 ,
+.Ic 3 ,
+.Ic 4
+or
+.Ic 5
+more rows.
+.It Ic status-format[] Ar format
+Specify the format to be used for each line of the status line.
+The default builds the top status line from the various individual status
+options below.
 .It Ic status-interval Ar interval
 Update the status line every
 .Ar interval
@@ -3669,6 +3683,7 @@ For example, to get a list of windows formatted like the status line:
 .Bd -literal -offset indent
 #{W:#{E:window-status-format} ,#{E:window-status-current-format} }
 .Ed
+.Pp
 A prefix of the form
 .Ql s/foo/bar/:
 will substitute
@@ -3872,8 +3887,9 @@ for the terminal default colour; or a hexadecimal RGB string such as
 Set the background colour.
 .It Ic none
 Set no attributes (turn off any active attributes).
-.It Xo Ic bright (or
-.Ic bold )
+.It Xo Ic bright
+(or
+.Ic bold ) ,
 .Ic dim ,
 .Ic underscore ,
 .Ic blink ,
@@ -3890,6 +3906,54 @@ Set an attribute.
 Any of the attributes may be prefixed with
 .Ql no
 to unset.
+.It Xo Ic align=left
+(or
+.Ic noalign ) ,
+.Ic align=centre ,
+.Ic align=right
+.Xc
+Align text to the left, centre or right of the available space if appropriate.
+.It Xo Ic list=on ,
+.Ic list=focus ,
+.Ic list=left-marker ,
+.Ic list=right=marker ,
+.Ic nolist
+.Xc
+Mark the position of the various window list components in the
+.Ic status-format
+option:
+.Ic list=on
+marks the start of the list;
+.Ic list=focus
+is the part of the list that should be kept in focus if the entire list won't fit
+in the available space (typically the current window);
+.Ic list=left-marker
+and
+.Ic list=right-marker
+mark the text to be used to mark that text has been trimmed from the left or
+right of the list if there is not enough space.
+.It Xo Ic range=left ,
+.Ic range=right ,
+.Ic range=window|X ,
+.Ic norange
+.Xc
+Mark a range in the
+. Ic status-format
+option.
+.Ic range=left
+and
+.Ic range=right
+are the text used for the
+.Ql StatusLeft
+and
+.Ql StatusRight
+mouse keys.
+.Ic range=window|X
+is the range for a window passed to the
+.Ql Status
+mouse key, where
+.Ql X
+is a window index.
 .El
 .Pp
 Examples are: