webmdshow/third_party: Add Xiph lib update script.

Add Xiph updater script that downloads libogg and libvorbis, and
then builds the libraries and installs the libs and includes.
Also add common/common.sh for common shell script utilities.

Change-Id: I2367b18ed1edc84cf9c1585409c1771909b1cd6c
webmdshow clean up: clang-format vp8decoder/vp8decoderpin.{c,h}pp

Change-Id: I39fb22e2734e4c3cd8c1652a9f8964e7a9c61f92
webmdshow clean up: clang-format vp8decoder/dllentry.cpp

Change-Id: Ib18b9c652d915827c6c7b77cbbe9826c4c12cf34
Merge "webmdshow/third_party: Add Xiph lib update script."
Merge "webmdshow clean up: clang-format vp8decoder/dllentry.cpp"
Merge "webmdshow clean up: clang-format vp8decoder/vp8decoderpin.{c,h}pp"