Merge top and onTop, so the position is flexible.

[sharp]

Merge top and onTop, so the position is flexible.

In the most time, user do not need popup exactly vertical align on middle of page

[galulex]

@SharpV Could you reproduce the bug here that makes you to do these changes please.

[sharp]

@galulex Hi, I realized that the problem is I did not add 'fixed: true' option , so if I scroll the window down, and click to popup, then the lazybox is beyond out of bound. After I read your code, I do not think it is one bug.

Now, I want to control the top position of lazybox, and ''top: 50' is perfect for me :)

[galulex]

@SharpV It is ok for me too but the ability to automatically calculate the top position must be here too. I pulled your repository to my demo and the position of lazybox was brocken. Developers should update the gem without breaking the application.