- Add ncurses patch 6.1-20180414
+ modify form library to optionally delay cursor movement on a field
edge/boundary (patch by Leon Winter).
+ modify form library to avoid unnecessary update of cursor position in
non-public fields (patch by Leon Winter).
+ remove unused _nc_import_termtype2() function.
+ also add/improve null-pointer checks in other places
+ add a null-pointer check in _nc_parse_entry to handle an error when
a use-name is invalid syntax (report by Chung-Yi Lin).

- Add ncurses patch 6.1-20180407
+ clarify in manual pages that vwprintw and vwscanw are obsolete,
not part of X/Open Curses since 2007.
+ use "const" in some prototypes rather than NCURSES_CONST where X/Open
Curses was updated to do this, e.g., wscanw, newterm, the terminfo
interface. Also use "const" for consistency in the termcap
interface, which was withdrawn by X/Open Curses in Issue 5 (2007).
As of Issue 7, X/Open Curses still lacks "const" for certain return
values, e.g., keyname().