+ remove wide-character checks from unctrl() (patch by Clemens Ladisch).
+ revise wadd_wch() and wecho_wchar() to eliminate dependency on
unctrl().
+ continue integrating "sp-funcs" by Juergen Pfeifer (incomplete).
+ add configure script --enable-sp-funcs to enable the new set of
extended functions.
+ start integrating patches by Juergen Pfeifer:
+ add extended functions which specify the SCREEN pointer for several
curses functions which use the global SP (these are incomplete;
some internals work is needed to complete these).
+ add special cases to configure script for MinGW port.
