Basic answer: Don't store compiled libraries and binaries in your Source repository. It's a source repository!
You can't ignore stuff under Subversion control and built items shouldn't be stored in Subversion in the first place. Delete them, then setup a svn:ignore
to ignore these directories when they get built. That way, no one accidently recommits these built binaries.
If you want to store binaries and libraries for later use, use a release repository for that. In fact, you can even set it up, so that your builds will automatically download .dlls they might need from other projects. A release repository could be something as simple as a directory on another system where these files are stored (and can be copied to your other projects), or something more complex like Artifactory or Nexus (used for Maven and Ivy projects. I don't think there's something similar for VS and C/C++ projects).
Or, you can use Jenkins to do your builds, and store these items as built artifacts in Jenkins jobs. When someone needs them, they can download them through Jenkins.