+ finish changes to wgetch(), making it switch as needed to the
window's actual screen when calling wrefresh() and wgetnstr(). That
allows wgetch() to get used concurrently in different threads with
some minor restrictions, e.g., the application should not delete a
window which is being used in a wgetch().
+ simplify mutex's, combining the window- and screen-mutex's.
+ add null-pointer checks in set_term() and delscreen().
+ move _nc_windows into _nc_globals, since windows can be pads, which
are not associated with a particular screen.
+ change use_screen() to pass the SCREEN* parameter rather than
stdscr to the callback function.
+ force libtool to use tag for 'CC' in case it does not detect this,
e.g., on aix when using CC=powerpc-ibm-aix5.3.0.0-gcc
(report/patch by Michael Haubenwallner).
+ override OBJEXT to "lo" when building with libtool, to work on
platforms such as AIX where libtool supports only static libraries
(report/patch by Michael Haubenwallner).
+ add configure --with-pthread option, for building with the POSIX
thread library.
+ continue implementing support for threading demo by adding mutex
for use_window().
+ add mrxvt terminfo entry, add/fix xterm building blocks for modified
cursor keys -TD
+ compile with FreeBSD "contemporary" TTY interface (patch by
Rong-En Fan).
+ add use_window() and use_screen() functions, to develop into support
for threaded library (incomplete).
+ fix typos in man/curs_opaque.3x which kept the install script from
creating symbolic links to two aliases created in 20070818 (report by
Rong-En Fan).
