ncurses 6.0 - patch 20160827

ncurses 6.0 - patch 20160827

+ add "v" menu entry to test/ncurses.c to show baudrate and other
  values.
+ add "newer" baudrate symbols from Linux and FreeBSD to progs/tset.c,
  lib_baudrate.c
+ modify CF_XOPEN_SOURCE macro:
  + add "uclinux" to case for "linux" (patch by Yann E. Morin)
  + modify _GNU_SOURCE for cygwin headers, tested with cygwin 2.3, 2.5
    (patch by Corinna Vinschen, from changes to tin).
+ improve CF_CC_ENV_FLAGS macro to allow for compiler wrappers such
  as "ccache" (report by Enrico Scholz).
+ update config.guess, config.sub from
	http://git.savannah.gnu.org/cgit/config.git