attached patches add three new features to newt:

  1. newtFormGetScrollPosition/newtFormSetScrollPosition
  2. newtEntryGetCursorPosition/newtEntrySetCursorPosition

     These are both because for what I'm doing, I sometimes need to
     destroy and recreate a form (after, eg, hiding or showing a
     component, or something similar that can't be done with the
     form "live"), and I want to recreate it in as close as
     possible to the same state as it was before. So these let me
     save some state before destroying it, and restore it after.

  3. implement newtComponentAddCallback for forms

     Makes newt forms use co->callback as a "focus-changed" callback.
     I'm actually not using this at the moment, but I've had various
     ideas involving it (eg, have the help line change to reflect the
     currently-focused component, or have entries that show "hint"
     text when they're empty and unfocused).