ALIASEE to help work with namespace aliases.
(struct sym): Remove struct member NAMESP_ALIASES.
(namespace_alias_table): New variable.
(make_namespace): Add parameter CONTEXT.
(check_namespace): New function.
(find_namespace): Add parameter CONTEXT.
(check_namespace_alias): New function.
(register_namespace_alias): Change type of parameter
OLD_NAME. Search for already defined alias in
NAMESPACE_ALIAS_TABLE.
(check_namespace): New function.
(enter_namespace): Call find_namespace with CONTEXT parameter.
(match_qualified_namespace_alias): New function.
(parse_qualified_ident_or_type): Fixed typo in comment. While
parsing qualified ident or type update namespace context and
restore it on exit.
(parse_qualified_param_ident_or_type): Fixed typo in comment.
(globals): Changed handling of namespace aliases.
(version): Added year 2001.
to semi-colon.
(FILENAME_EQ): New macro, for comparing file names.
(add_member_decl, add_global_decl, add_member_defn): Use
FILENAME_EQ.
(process_file): Don't assume that fread always reads as many bytes
as it was told to (DOS-style CR-LF text files fail this logic).
(open_file): Allocate enough space for path->path plus the file
name and the slash.
