subversion: fix for Security Advisory CVE-2013-4131
The mod_dav_svn Apache HTTPD server module in Subversion 1.7.0 through
1.7.10 and 1.8.x before 1.8.1 allows remote authenticated users to cause
a denial of service (assertion failure or out-of-bounds read) via a
certain (1) COPY, (2) DELETE, or (3) MOVE request against a revision
root.