Squashed commit of the following:

commit 460c9d4f291993e2a0cf5ead8390a12e3fe654a8
Author: iyatomi takehiro <iyatomi@gmail.com>
Date:   Thu Jan 10 23:15:33 2013 +0900

    change msgpack js version (apply my fix for stream codec)

commit 2d29ecd35b7c90bbe7e0dd96ff547bac37f298ea
Author: iyatomi takehiro <iyatomi@gmail.com>
Date:   Thu Jan 10 23:01:55 2013 +0900

    rewrite timer module to allow multiple os timer and taskgrp (light weight timer)
    fix bug that test suite does not throw error correctly even if actual error occurs

commit b7458e6679d157f675e3224cbcec010ce55c1002
Author: iyatomi takehiro <iyatomi@gmail.com>
Date:   Tue Dec 25 06:10:22 2012 +0900

    prevent next timer callback from executing before previous timer callback execution finished.
Merge pull request #16 from umegaya/pr/new_timer

Squashed commit of the following: