Stop the player from streaming past the availability range

Created by: robertbryer

In DashHandler.setup(), StreamProcessor isn't available, so isDynamic() returns null.

This means the getters in segmentController were being generated with isDynamic set to null, so they would act as though the manifest was static and take the segment availablility as being the same as the manifest availablility. https://github.com/Dash-Industry-Forum/dash.js/blob/18647a32064feec61ca33438eb16bfb0319232a4/src/dash/controllers/SegmentsController.js#L58

This fixes the problem by moving the isDynamic() call to initialize instead.

This is a fix for #3008 (closed)