[PATCH 00/24] Horizontal TUI layout + windows in Python

[Tom Tromey <tom at tromey dot com>]

This series adds some new features to the TUI: user-defined layouts,
horizontal layouts, and the ability to write windows in Python.

Much of the series is refactoring in preparation for the new
additions.

A couple of other visible changes were needed.  It wasn't entirely
clear to me how the C-x 1 and C-x 2 bindings should be handled; see
patch 4 and patch 5.

The Python API is currently pretty simple.  I may add some new
features to it.  For example, right now you can't write a replacement
for the locator window, because there's no way for a Python window to
set its maximum size.  It might also be useful to have a mode where
gdb manages scrolling, rather than having to do it manually in Python;
or a way to control whether wrapping is done when writing to a window.

I didn't add a "winwidth" command to change the width of a window.
Perhaps this is needed.  Also maybe "info win" should show more
information now?

Let me know what you think.

Tom