Create 1.8.x backport branch for r1684077. Update code in svndiff.c since MAX_ENCODED_INT_LEN was renamed to SVN__MAX_ENCODED_UINT_LEN in trunk. git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x-r1684077@1684114 13f79535-47bb-0310-9956-ffa450edef68