Add cmd line option to control loopfilter for vpxenc
Add cmd line option to control loopfilter for vpxenc

Change-Id: I4f5e6ce2f1b535a586bdb6c9e55a3d49ebf61af4

webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx