Updating Opus to a pre-release of 1.1

This CL updates Opus to a pre-release of the coming Opus 1.1 version. The code is extracted from http://git.xiph.org/?p=opus.git, commit aee4d8057632ea0cfc1d55d88acf8466b47b7b4b from October 1st 2013.
This version includes both algorithmic and platform optimizations, as well an important fix for a denorm problem when the input goes silent after active audio. The problem causes high CPU usage.

Review URL: https://codereview.chromium.org/28553003

git-svn-id: svn://svn.chromium.org/chrome/trunk/deps/third_party/opus@230378 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/opus.pc.in b/opus.pc.in
index b7d4083..e15c6fe 100644
--- a/opus.pc.in
+++ b/opus.pc.in
@@ -12,5 +12,5 @@
 Requires:
 Conflicts:
 Libs: -L${libdir} -lopus
-Libs.private: @PC_LIBM@
+Libs.private: @LIBM@
 Cflags: -I${includedir}/opus