HAMMER de-dup in master

[Matthew Dillon]

:
:If it's experimenal, what's the point of MFCing it to 2.8?
:
:Petr

    There are two pieces here.  There is the HAMMER version 5 support,
    and there's the de-dup feature itself.  The version 5 support will
    be MFC'd fairly quickly, because it's really minor and that way
    4.8 will not complain if you try to mount a version 5 hammer you
    created on master on it.

    The de-dup feature itself will not until we get better testing under
    our belt.

    					-Matt
					Matthew Dillon 
					<dillon at backplane.com>