Turning on mpsafe mode by default in master

[Matthew Dillon]

    I'm going to remove the mplock shims in our global tokens in
    master, essentially running the related code mpsafe from this point
    on.

    There are still numerous global code bits that use the mplock
    directly, though mostly out of the critical path now.

    The next major bit of work to improve MP performance is going to be
    dealing with wide-ranging vm_token.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>