Needed because our configure.mk assumes it can blindly use unknown

configure options and livbpx doesn't actually use GNU autoconf.

Not appropriate for upstream.

--- libvpx-1.4.0/build/make/configure.sh 2015-04-03 11:49:19.000000000 -0700

+++ libvpx-1.4.0/build/make/configure.sh 2015-06-12 13:11:14.117716080 -0700

@@ -13,6 +13,11 @@

#

# Logging / Output Functions

#

+warn_unknown(){

+ echo "Ignoring unknown option \"$1\"."

+ echo "See $0 --help for available options."

+}

+

die_unknown(){

echo "Unknown option \"$1\"."

echo "See $0 --help for available options."

@@ -567,7 +572,7 @@

show_help

;;

*)

- die_unknown $opt

+ warn_unknown $opt

;;

esac

done