JiaLiPassion and mhevery feat(eventListener): fix #798, improve EventTarget.addEventListener p…
…erformance (#812)

* feat(performance): fix #798, improve EventTarget.addEventListener performance

* add test cases

* add comment to explain the implementations

* add test cases for resschedule eventTask

* add IE/edge and cross context check

* modify document for extra flags

* minor changes, define some const, move logic into __load_patch

* let nodejs use new addListener/removeListener method

* add nodejs test example

* add eventListeners/removeAllListeners test cases for browser
Latest commit b3a76d3 Jun 30, 2017