Just two days before the release of his much-anticipated fourth full-length, pop star Justin Bieber revealed the dates Wednesday for a massive tour of North America next spring and summer.  The 58-stop trek kicks off March 9th at Seattle's KeyWest Arena, winding across the US and into Canada before wrapping up on Jlu 18th at New York City's Madison Square Garden.  Click Here for a complete rundown of dates and venues.  Titled Purpose, Bieber's latest album hits shelves on Friday.