private Float decodeFloat(byte[] in) {
    assert in.length == 5 : "Wrong length for a float";
    Integer l = decodeInteger(in);
    return Float.valueOf(Float.intBitsToFloat(l.intValue()));
  }
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