+20080614
+ + modify test/ditto.c to illustrate multi-threaded use_screen().
+ + change CC_SHARED_OPTS from -KPIC to -xcode=pic32 for Solaris.
+ + add "-shared" option to MK_SHARED_LIB for gcc on Solaris (report
+ by Poor Yorick).
+
+20080607
+ + 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.
+
+20080531
+ + modify wgetch() to use the screen which corresponds to its window
+ parameter rather than relying on SP; some dependent functions still
+ use SP internally.
+ + factor out most use of SP in lib_mouse.c, using parameter.
+ + add internal _nc_keyname(), replacing keyname() to associate with a
+ particular SCREEN rather than the global SP.
+ + add internal _nc_unctrl(), replacing unctrl() to associate with a
+ particular SCREEN rather than the global SP.
+ + add internal _nc_tracemouse(), replacing _tracemouse() to eliminate
+ its associated global buffer _nc_globals.tracemse_buf now in SCREEN.
+ + add internal _nc_tracechar(), replacing _tracechar() to use SCREEN in
+ preference to the global _nc_globals.tracechr_buf buffer.
+
+20080524
+ + modify _nc_keypad() to make it switch temporarily as needed to the
+ screen which must be updated.
+ + wrap cur_term variable to help make _nc_keymap() thread-safe, and
+ always set the screen's copy of this variable in set_curterm().
+ + restore curs_set() state after endwin()/refresh() (report/patch
+ Miroslav Lichvar)
+