Remove Opus from DEPS and import a local copy

third_party/opus/src/win32/genversion.bat

Index: third_party/opus/src/win32/genversion.bat
diff --git a/third_party/opus/src/win32/genversion.bat b/third_party/opus/src/win32/genversion.bat
new file mode 100755
index 0000000000000000000000000000000000000000..cd1d4dce6ed8f5486ee31a3f5a14dab8bc038e0c
--- /dev/null
+++ b/third_party/opus/src/win32/genversion.bat
@@ -0,0 +1,46 @@
+@echo off
+
+setlocal enableextensions enabledelayedexpansion
+
+for /f %%v in ('git --git-dir="%~dp0..\.git" describe --tags --match "v*"') do set version=%%v
+
+if not "%version%"=="" goto :gotversion
+
+if exist "%~dp0..\version.mk" goto :getversion
+
+echo Git cannot be found, nor can version.mk. Generating unknown version.
+
+set version=unknown
+
+goto :gotversion
+
+:getversion
+
+for /f "delims== tokens=2" %%v in (%~dps0..\version.mk) do set version=%%v
+
+set version=!version:^"=!
+set version=!version: =!
+
+:gotversion
+
+set version_out=#define %~2 "%version%"
+set version_mk=%~2 = "%version%"
+
+echo %version_out%> "%~1_temp"
+
+if %version%==unknown goto :skipgenerate
+
+echo # static version string; update manually every release.> "%~dp0..\version.mk"
+echo %version_mk%>> "%~dp0..\version.mk"
+
+:skipgenerate
+
+echo n | comp "%~1_temp" "%~1" > NUL 2> NUL
+
+if not errorlevel 1 goto exit
+
+copy /y "%~1_temp" "%~1"
+
+:exit
+
+del "%~1_temp"