Fixed ordering bugs for Monotone Chain
Fixed ordering bugs for Monotone Chain

If points x or y were identical points would appear in both right and left lists.

slightair/SwiftGraphics,hejunbinlan/SwiftGraphics,rhcad/SwiftGraphics,slightair/SwiftGraphics,sdesimone/SwiftGraphics,hejunbinlan/SwiftGraphics,Pretz/SwiftGraphics,rhcad/SwiftGraphics,SheffieldKevin/SwiftGraphics,rhcad/SwiftGraphics,sdesimone/SwiftGraphics,sdesimone/SwiftGraphics,hejunbinlan/SwiftGraphics,SheffieldKevin/SwiftGraphics,slightair/SwiftGraphics,sdesimone/SwiftGraphics,Pretz/SwiftGraphics,marinehero/SwiftGraphics,Pretz/SwiftGraphics,hejunbinlan/SwiftGraphics,marinehero/SwiftGraphics,marinehero/SwiftGraphics,Pretz/SwiftGraphics,rhcad/SwiftGraphics,SheffieldKevin/SwiftGraphics,slightair/SwiftGraphics,marinehero/SwiftGraphics