Added check for SVN WebDAV auth request (http://subversion.apache.org/docs/api/latest/group__svn__dav__error.html#gada0137a4ffc40251d2fce8ba06ca2e14, http://svn.apache.org/repos/asf/subversion/trunk/subversion/bindings/javahl/src/org/tigris/subversion/javahl/ErrorCodes.java).
Merge pull request #1990 from phansys/svn-auth

Added check for SVN WebDAV auth request