Fix that removed values/namespaces remain in the session storage

fixes #5934
Make it possible to save the session by its associated session namespaces
Improve failure handling when setting the locale
Fix division by zero in Perfdata.php

Fixes #5708

Signed-off-by: Michael Friedrich <Michael.Friedrich@netways.de>
Fix that the general and logging form cannot write configuration changes

fixes #5952
Add form field to set the database name for a resource of type db

fixes #5115
More code style
Intendation
Allow developers to disable minimizers
Fix that the preference configuration does not handle defaults properly
Refactor PreferencesStore and IniStore

refs #5682
Rewrite preference DbStore

refs #5682
Merge branch 'bugfix/preference-dbstore-broken-5682'

fixes #5682
Re-enable setting the current configuration when showing icingaweb/config

fixes #5972
Fix exception on 404 in monitoring/show/
Test: Using autoloader for tests

refs #4639
Clean up tests [WIP]

refs #4639
Drop obsolete test cases

refs #4639
Drop BaseTestCase static class loader

refs #4639
Refactor php unittest bootstrapping

refs #4639