I figured out how to get SVN working, and so it is now set up, at http://svn.pyrzqxgl.org/svnroot/jmediawiki/. I will eventually change the product name (that name is unsuitable for publication because of trademark issues), but I want to wait to do that until I have the code sufficiently syntax-valid to use Eclipse's refactoring methods.

Substantial hints on getting SVN working within Apache2 were garnered from this howto at Sourceforge. My thanks to whoever "bertheymans" is.