Set write deadline, not read deadline
Add ability to abort all FD syscalls

Barret built this into the kernel, and I added the code on the GO side
to use it. Linux does the same sort of thing by eviciting all fds
waiting on a poll descriptor. We need to explicitly abort them.
Fix up / skip some of the net/http tests
We actually return a real ERRNO on timeout now
Need to copy some more files over for a gotest

Only applies to the benchmarks, but still needed