Correctly report which version of libncurses was linked

Later versions of ncurses (20111030 and up) support NCURSES_WIDECHAR even when
compiling with libncurses instead of libncursesw.

Have tig correctly report whether it was linked against libncursesw or
libncurses based off the same defines we set in the build script and use to
determine which headers to include.

Per the build system, either of HAVE_NCURSESW_H or HAVE_NCURSESW_CURSES_H may
indicate the presence of ncursesw, so both are checked.

(See #1240 as an example of where `tig --version` incorrectly reports `ncursesw`
instead of `ncurses`).

src/tig.c

@@ -557,7 +557,7 @@ parse_options(int argc, const char *argv[], bool pager_mode)
 				printf("tig version %s\n", TIG_VERSION);
 #ifdef NCURSES_VERSION
 				printf("%s version %s.%d\n",
-#ifdef NCURSES_WIDECHAR
+#if defined(HAVE_NCURSESW_CURSES_H) || defined(HAVE_NCURSESW_H)
 				       "ncursesw",
 #else
 				       "ncurses",