line-mesh-demo using setIndexRange(). When changing mode it doesn't recreate the index buffer, but changes the range of indices to draw and the type of primitives.
line-mesh-demo using setIndexRange(). When changing mode it doesn't recreate the index buffer, but changes the range of indices to draw and the type of primitives.

added interface to modify number of used elements from the elements array.

Change-Id: If0b223e6ace3d64aae8f16af0a284a42a7c9d967

dalihub/dali-demo,dalihub/dali-demo,dalihub/dali-demo,dalihub/dali-demo