Session responder lock fix for QFJ-421 got reverted in SVN

The one-line fix for QFJ-421 in Mar 2009 (r921) seems to have been accidentally reverted in Jan 2010 by r928.

Why not use an idiom such as:

private final Object responderSync = new byte[0];

Others may prefer simply a new Object() for a lock like this. I think the debate[1] over bytecode size or whatever is moot, but clearly a String was a bad choice here for maintainability reasons, i.e. it just looks like a constant value suitable to be interned.

[1] http://java.itags.org/java-core-apis/32998/ "Java Core APIs: locks: Object versus empty byte array"