rebase to chrome 38
make nw run as node

Part of rogerwang/node-webkit#213
add uv_pending_reqs
add uv_async_send_nw
don't insert same req into pending list again

Or we'll have loop in the list when the async req
is inserted again by uv_async_send_nw

Fix rogerwang/node-webkit#2332
rebase fix for nw11
Merge remote-tracking branch 'origin/nw' into nw11