Fixes a bug with CPCursor push method.

Before when you pushed a cursor on stack the currentCursor variable was assigned with a number (cursorStack.push(self) returns length of the elements). So when after pushing a cursor you wanted to set it like this: [[CPCursor currentCursor] set] you got an error [CPNumber set] unrecognised selector sent to instance…

This fix assigns the last cursor on stack to currentCursor variable so this error is not occurring anymore.