Search for wide-character ncurses when configuring

[CONFIGURATION]
* BUG: gb.ncurses now compiles on systems which only provide wide-character versions of ncurses pkg-config files.

gb.ncurses/configure.ac

@@ -7,9 +7,21 @@ AC_CONFIG_MACRO_DIR([m4])
 GB_INIT(gb.ncurses)
 AC_PROG_LIBTOOL
 
+# Most distributions I have seen apparently provide the ncurses and panel
+# pkg-config files (which may be synonymous with ncursesw and panelw for
+# wide-character support). Solus only provides the *w versions.
+#
+# We should prefer linking with the wide-character version but still
+# allow to compile on systems that don't have ncursesw pkg-config files.
+pkg-config --silence-errors --exists ncursesw panelw
+if test $? -eq "0"
+  then gb_ncurses_pkgconfig_names="ncursesw panelw"
+  else gb_ncurses_pkgconfig_names="ncurses panel"
+fi
+
 GB_COMPONENT_PKG_CONFIG(
   ncurses, NCURSES, gb.ncurses, [src],
-  ncurses panel)
+  $gb_ncurses_pkgconfig_names)
 
 AC_OUTPUT( \
 Makefile \