Revise support for We Heart It #89

* Revise WeHeartIt Model #89
* Fix WeHeartIt's Post #89
* Add support for WeHeartIt's Tags
* WeHeartIt: Add ORIGIN & ENTRY_URL & checkLogin()
* WeHeartIt: Remove URL & iHeartIt() & getAuthCookie()

* Revise "Photo - We Heart It" Extractor for WeHeartIt's favor()
* "Photo - We Heart It" Extractor should get Original Size Image
* "Photo - We Heart It" Extractor: Add RE & getEntryID()

Close #89