ncurses 5.6 - patch 20071013

+ modify makefile rules to allow clear, tput and tset to be built
  without libtic.  The other programs (infocmp, tic and toe) rely on
  that library.
+ add/modify null-pointer checks in several functions for SP and/or
  the WINDOW* parameter (report by Thorben Krueger).
+ fixes for field_buffer() in formw library (see Redhat Bugzilla
  #310071, patches by Miroslav Lichvar).
+ improve performance of NCURSES_CHAR_EQ code (patch by Miroslav
  Lichvar).
+ update/improve mlterm and rxvt terminfo entries, e.g., for
  the modified cursor- and keypad-keys -TD