add Ajax docs

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
add missing property

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
add a polyfill for Function.prototype.bind for OLD platforms that do not have it

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
docs for Async

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
docs for AjaxProperties

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
docs for cookie

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
docs for FormData

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)