When persistent inventory window is first populated, focus is given to
its window (behavior might be window manager-specific; it happens with
default window manager on OSX).  Focus should be explicitly directed
back to the main window.

More focus:  although the menu window gets focus, the menu inside that
window does not accept focus, so scrolling persistent inventory via
keyboard won't work.  [Does not affect the new '|' command which takes
input via yn_function() rather than directly from the perm_invent menu.]

When persistent inventory window is displayed, an update that ought to
make it grow won't do so even if there is room on the screen for that.
It will add scrollbar(s) when not already there, and it can be resized
manually.

If the permsistent inventory window is manually made taller, it will
fill that space immediately.  But if it is made wider, handling of the
extra space seems to be erratic and it is sometimes left blank until
window is dismissed and re-created via 'i' or toggling 'perm_invent'.

When the map is clipped, sometimes panning leaves a gap in the display.
Test case was with the map manually resized to avoid overlap with the
persistent inventory window (resizing added scrollbars which hadn't
been there previously).  The level was fully mapped and hero was in a
room on the left side; clicking on horizontal scrollbar to pan to the
right rendered the map correctly.  However, issuing a command that
caused the map to auto-pan back to show the hero didn't render it
correctly.  A portion of map which had been hidden beneath the vertical
scrollbar while panned got moved into the middle of the window but got
shown there with a vertical strip of unrendered background that was
approximately half the width of the vertical scrollbar.  It wasn't
inserted space in between two sides of map; it was undrawn map.  If it
had been drawn, the map would have been normal.

Menus which have entries that are too wide to display have their wide
lines truncated rather than adding a horizontal scrollbar.  Resizing
larger doesn't recover truncated text and resizing smaller truncates
even more.

