Minor improvements

(cherry picked from commit efce377cfdbbe0bc1ca58cde66f29c2b2c0d531f)
WICKET-5473 Wicket does not handle non in-memory Httpsessions correctly

Mark the session dirty when incrementing the sequences for bound sessions
WICKET-5492 WebApplication ignores a SecurityException when reading the configuration type
WICKET-5493 Disable jar indexing
WICKET-5491 Wicket.DateTime.getViewportHeight() returning undefined on IE8, positions calendar out of viewport