improve ping api
use ping() in setPing()
use indexof component for ie8 and below
Merge pull request #157 from goinstant/indexof

use indexof component for ie8 and below
Does not emit close on incorrect socket connection
Merge pull request #154 from sweetieSong/fix/issue-168

fix issue/168
engine.io: updated build
Merge pull request #150 from jphire/fix/104_improve_ping_api

Fix/104 improve ping api
Release 0.6.0
engine.io: fixed build
Release 0.6.1
Makefile: extra precaution when building to avoid 0.6.0 build problem
transports: really fix iOS crash issue
socket: code style
socket: don't call `socket#onclose` if previous state was not `open`
socket: added missing `socket#onerror` support
socket: ignore further transport communication upon `onClose`
transports: improve polling orderly close (fixes #164)
Release 0.6.2
use http url