added unit test (extracted from Prototype 1.6) running fine with Java 6 but not with Java 7 or 8

git-svn-id: svn://svn.code.sf.net/p/htmlunit/code/trunk@9348 5f5364db-9458-4db8-a492-e30667be6df6
upgrade svnkit to 1.8.3-1 to handle SVN 1.8 file format

git-svn-id: svn://svn.code.sf.net/p/htmlunit/code/trunk@9349 5f5364db-9458-4db8-a492-e30667be6df6