svn doesn't deal with unknown vhosts or repos well

[adehnert]

While working on #166 (git doesn't handle unknown vhosts), I looked briefly at svn's behavior:

alex@kronborg tmp [03:31] $ svn co svn://scripts.scripts.mit.edu/aoeueoau
svn: No repository found in 'svn://scripts.scripts.mit.edu/aoeueoau'
alex@kronborg tmp [03:32] $ svn co svn://asa.scripts.mit.edu/aoeueoau
svn: Malformed network data
alex@kronborg tmp [03:32] $ svn co svn://asaaoeuaeou.scripts.mit.edu/aoeueoau
svn: Malformed network data

Now, svn, unlike git, doesn't actually report the weird error messages that svnproxy.pl and ldapize.pl (respectively, for the last two examples above) spew out, so this vaguely matters less than git (also, I don't care much about svn), but theoretically it might be nice to fix this.

[adehnert]

Anders' changes have improved the state for the third case. The second is not fixed.

alex@kronborg scripts [02:05] $ svn co svn://scripts.scripts.mit.edu/aoeueoau
svn: No repository found in 'svn://scripts.scripts.mit.edu/aoeueoau'
alex@kronborg scripts [02:06] $ svn log svn://asa.scripts.mit.edu/aoeueoau
svn: Malformed network data
alex@kronborg scripts [02:06] $ svn log svn://aoeuoaeuaoeu.scripts.mit.edu/aoeueoau
svn: No repository found in 'svn://aoeuoaeuaoeu.scripts.mit.edu/aoeueoau'

[adehnert]

(Oh, yeah, this partially duplicates #88...)