fixes #144

Merge branch 'fixes_144' into releases/3.0.0
fixed #155
more null checks for statementcontroller
cleaning up the grid visualizer code and implement stuff for displaying token annotations in the grid
do not filter by namespace when adding token annotations to grid visualizer
updated javadoc
Merge branch 'tokengrid'
fixing #158
fixing the install documentation
wrong header id
updated documentation about the anonymous group and how to start ANNIS without authentification
changing the default security configuration from /etc/annis/user_config_trunk to /etc/annis/user_config
release instructions updated
fixed #157 (Add CorefVisualizer that is only using the result context)
updated CHANGELOG
updating version numbers to 3.0.0
Finish annis-3.0.0