fix processing of large bulks (above 2GB)

- protocol parsing (processMultibulkBuffer) was limitted to 32big positions in the buffer
  readQueryFromClient potential overflow
- rioWriteBulkCount used int, although rioWriteBulkString gave it size_t
- several places in sds.c that used int for string length or index.
- bugfix in RM_SaveAuxField (return was 1 or -1 and not length)
- RM_SaveStringBuffer was limitted to 32bit length

src/rio.h

@@ -130,7 +130,7 @@ void rioInitWithFdset(rio *r, int *fds, int numfds);
 
 void rioFreeFdset(rio *r);
 
-size_t rioWriteBulkCount(rio *r, char prefix, int count);
+size_t rioWriteBulkCount(rio *r, char prefix, long count);
 size_t rioWriteBulkString(rio *r, const char *buf, size_t len);
 size_t rioWriteBulkLongLong(rio *r, long long l);
 size_t rioWriteBulkDouble(rio *r, double d);