I've noticed this board runs on Vanilla 1.0.1. I assumed doing an update check that there was a new version available, but there isn't. So I thought it will be the next release? Is it the development version? If so, we could help Mark with some bugfixes.
1) I use the extension.php in a few of my extensions. But it hasn't been included in the Friendly Url extension and also the settings.php is missing the REWRITE_extension.php
If you found any other (minor) bugs, add them here. I suggest NO CHANGES or FEATURE REQUESTS, as I don't think Mark is planning anything in changing the core (I might be wrong there as his mind is so full with ideas :P)
Ok, before anyone goes venturing any further: let it be known that SVN is for developmental and testing purposes only and it can create more problems than solve if you decide to run and use it. In a nutshell, it's not always stable or expected to be used in deployment... using a SVN copy live is doing so at your own risk.
But to answer your question on the SVN client, that depends what platform you're running under. If it's windows, I suggest TortiseSVN.