third_party/update_libs.sh: use vs2013 libvpx targets

Change-Id: I2b10159d7eb78c1266c63284d2901e995d52f5e5
third_party/libvpx: Update to v1.3.0-4686-g897500b

- Remove unsupported VPx filter projects.
- Remove 2010 suffix from VPx filter project file names.
- Remove 2010 suffix from webmdshow solution file name.
- Update platform toolset for VPx filters to vs2013 (v120).
- Fix libvpx API change induced compile errors.

Change-Id: I8a1425669d9226d590265516831b2585e5ea770a