private Long decodeLong(byte[] in) {
    long rv = 0L;
    for (int idx = 1; idx < in.length; idx++) {
      byte i = in[idx];
      rv = (rv << 8) | (i < 0 ? 256 + i : i);
    }
    return Long.valueOf(rv);
  }
Handles old whalin (tested with v1.6) encoding: data type is in the first
byte of the value.

@author bpartensky
@since Oct 16, 2008
src/main/java/net/spy/memcached/transcoders/WhalinV1Transcoder.java