Heads up: resident executable support added

[Matthew Dillon]

    Update on resident executable support.  It seems to be working very
    well, I am seeing one possible bug in that when I resident the
    entire contents of /usr/bin make buildworld sometimes fails in the
    middle.  I'm doing multiple buildworld runs to characterize the
    problem.  I'm not entirely convinced that the resident code is at
    fault, it could simply be that the code is bringing a bug in
    vmspace_fork() to light.

						-Matt