Fix columns used for $status_format and $pager_format in the pager.

Fix columns used for $status_format and $pager_format in the pager.

The code was hardcoding use of MuttIndexWindow->cols in
mutt_make_string_info() and MuttStatusWindow->cols in
menu_status_line().

Add a parameter to mutt_make_info_string().  Change menu_status_line()
to use menu->statuswin->cols, falling back to MuttStatusWindow if no
menu is passed in.

Set menu->statuswin appropriately inside pager.c.

Thanks to Richard Russon for tracking down this problem, and for the initial patch.