Add lazy loading on scroll

[LidoDev]

Lazy loading is missing on scroll event. The list mentions may be opened top when container bottom is not visible, i think it will be pretty to add an option for overriding this behavior to let client configuring the view to be opening to bottom or top. i will create a pull request on this.
#101

[MadSpindel]

We have a defaultMenuOrientation. Could we use that one to get the result that you want? I believe you are asking for something like "forceTop" or "forceBottom"?

[LidoDev]

Yes, but the current behavior is that when bottom is not visible we override defaultMenuOrientation. Yes we can use it with forceBttom or forceTop or we change the type to json
defaultMenuOrientation:{
orienation : ennum ['bottom', 'top'],
force: boolean
}.

In the same commit there is the lazy loading on scroll event.

[sidharthancr]

Please add this in. Badly needing this feature @MadSpindel