use locale-indep. c_is* functions for parsing, not isspace, isprint etc

use locale-indep. c_is* functions for parsing, not isspace, isprint etc

* src/parse-gram.y: Include "c-ctype.h".
(add_param): Parse with c_isspace, not isspace.
* src/parse-gram.c: Likewise.
* src/scan-gram.l: Include c-ctype.h, not ctype.h.
(SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER): Use c_isspace and c_isprint,
not ctype.h's locale-dependent functions.