Update experimental modules' version numbers due to 6.9.1
WICKET-5316: fixed synchronization problem in page access
upgrade stupid eclipse settings to 6.10
WICKET-5316: boolean flag should be volatile
WICKET-5316: testcase showing the problem with lock releases
Start next development version
Merge remote-tracking branch 'origin/wicket-6.x' into wicket-6.x
WICKET-5322 "Source code" link doesn't work at wicket-library.com

Simplify SourcesPage.
Add log4j as compile dependency because the examples failed at start with ClassNotFoundException org/apache/log4j/Level
WICKET-5319 do not encrypt full urls