Ninja: $ORIGIN not properly escaped in response files

If the Ninja generator decides to use a response file, any \$$ORIGIN occurance from the build.ninja ends up as \$ORIGIN in the response file, causing also \$ORIGIN to occur in the resulting .so or executable.

Not sure whether it is rather a Ninja or a CMake issue, but my suggestion would be to at least have the option to prevent the linking options being pushed to the response file.