+ minor portability fixes for MinGW:
+ ensure WINVER is defined in makefiles rather than using headers
+ add check for gnatprep "-T" option
+ work around bug introduced by gcc 4.8.1 in MinGW which breaks
"trace" feature:
http://stackoverflow.com/questions/20877689/gcc-4-8-1-minggw-d-option-does-not-work-as-usual
+ fix most compiler warnings for Cygwin ncurses-examples.
+ restore "redundant" -I options in test/Makefile.in, since they are
typically needed when building the derived ncurses-examples package
(cf: 20140726).
+ move definition for NCURSES_WRAPPED_VAR back to ncurses_dll.h, to
make includes of term.h without curses.h work (report by "Nix").
+ continue integrating "sp-funcs" by Juergen Pfeifer (incomplete).
