ncurses 6.0 - patch 20170218

ncurses 6.0 - patch 20170218

+ fix several formatting issues with manual pages.
+ correct read of terminfo entry in which all strings are absent or
  explicitly cancelled.  Before this fix, the result was that all were
  treated as only absent.
+ modify infocmp to suppress mixture of absent/cancelled capabilities
  that would only show as "NULL, NULL", unless the -q option is used,
  e.g., to show "-, @" or "@, -".