ncurses 6.1 - patch 20180825

ncurses 6.1 - patch 20180825

+ add a section to tput manual page clarifying how it determines the
  terminal size (prompted by discussion with Grant Jenks).
+ add "--disable-relink" to rpm test-packages, for consistency with the
  deb test-packages.
+ split spec-file into ncurses6.spec and ncursest6.spec to work around
  toolset breakage in Fedora 28.
+ drop mention of "--disable-touching", which was not in the final
  20180818 updates.