Add basic stdio stream (FILE*) handling. Implemented fopen/fclose/fwrite/fread without buffering support. Added strict symbol listing to ulibc via symbols.def (still some internal symbols are exposed for unimplemented function, like __ulibc_printf. Added some POSIX creation mode flags (O_TRUNC, O_APPEND). Renamed typo O_CREATE to O_CREAT. Remove debug junk from coreutils.