Description

URLFor returns url string with another registered controller handler with params.

	usage:

	URLFor(".index")
	print URLFor("index")
 router /login
	print URLFor("login")
	print URLFor("login", "next","/"")
 router /profile/:username
	print UrlFor("profile", ":username","John Doe")
	result:
	/
	/login
	/login?next=/
	/user/John%20Doe

 more detail http://beego.me/docs/mvc/controller/urlbuilding.md