ncurses 6.0 - patch 20171230

ncurses 6.0 - patch 20171230

+ build-fix for ncurses-examples with Fedora27, adding check for
  reset_color_pairs() -- not yet in Fedora's package.
+ consistently add $CFLAGS to $MK_SHARED_LIB symbol in configure
  script when the latter happens to use the C compiler rather than
  directly using the loader (report by Jeffrey Walton).
+ set ABI for upcoming 6.1 release in "*.map" files.  While there are
  some remaining internals to apply, no ABI-related changes are
  anticipated.
+ add configure --with-config-suffix option to work around filename
  conflict with Redhat packages versus test-packages.