#213 hidden dynmenu doesn't redisplay cursor

[Matthew Emmerton]

When a dynamic menu is hidden (ie, browse menu, hit
*), and an option is selected, the cursor is not
redisplayed.

This makes understanding where input is being
requested difficult.

The method used to show/hide the cursor is sound; we
just need to pay attention to every exit path from the
dynmenu processing code and re-enable the cursor
when doing so.