Undo most of the 2007-02-03 change, switching to the strcase module

now that gnulib strcase has been fixed.
* bootstrap.conf (gnulib_modules): Remove c-strcase.  Add strcase.
* lib/.cvsignore: Remove c-ctype.c, c-ctype.h, c-strcase.h,
c-strcasecomp.c, c-strncasecmp.c.  Add strcasecmp.c, strncasecmp.c
* m4/.cvsignore: Add strcase.m4.
* src/getargs.c: Revert 2007-02-03 change, as follows.
Don't include c-strcase.h.
(language_argmatch): Use strcasecmp rather than c_strcasecmp.
strcasecmp has "unspecified behavior" outside the POSIX locale,
but it works fine in practice if at least one argument is ASCII,
as is the case in Bison.

lib/.cvsignore

@@ -4,11 +4,6 @@ Makefile.in
 argmatch.c
 argmatch.h
 basename.c
-c-ctype.c
-c-ctype.h
-c-strcase.h
-c-strcasecmp.c
-c-strncasecmp.c
 config.h
 config.hin
 configmake.h
@@ -51,10 +46,12 @@ stdint_.h
 stdio--.h
 stdio-safer.h
 stpcpy.c
+strcasecmp.c
 strerror.c
 string.h
 string_.h
 stripslash.c
+strncasecmp.c
 strndup.c
 strnlen.c
 strtol.c