EMF+: Render custom line cap data.

Change-Id: Ic5e2e2d105fb006503b63e4e162d4dc09dab9e68
EMF+: Set the stroke attributes on the custom line caps.

This finally makes the rendering of the custom line caps nice & complete.

Change-Id: If35ef1c44f34f5d5e6c50789c907105d03e96fca