Land b1_x onto b_release_1_6_7 (20081219_1440)

Land b1_x onto b_release_1_6_7 (20081219_1440)
b=18078
i=liang

Land lnet b1_x (the lnet gate branch has already been merged to b1_x) to
b_release_1_6_7 since many lnet fixes which were intended to be in 1.6.7
have only been landed to the lnet gate branch, but not on the lnet b1_x
& b_release_1_6_7 branches. Liang checked the diff and confirmed that
there is nothing that should not go to 1.6.7 here.