+ compiler warning fixes for test programs.
+ various build-fixes for test-programs with pdcurses.
+ updated configure checks for X packages in test/configure from xterm
#267 changes.
+ add configure check to gnatmake, to accommodate cygwin.
+ correct limit-check in wredrawln, accounting for begy/begx values
(patch by David Benjamin).
+ fix most compiler warnings from clang.
+ amend build-fix for OpenSolaris, to ensure that a system header is
included in curses.h before testing feature symbols, since they
may be defined by that route.