Do not require ApplicationBootstrap in index.php

refs #5638
fixes #5529
Do not set UTC in index.php

refs #5638
fixes #5530
Do not exit the application when the logger has errors logged during bootstrap and stop preference loading on every request

Only fatals should exit the application.
Preferences must be loaded only once after login.
Revert "Change setup behavior of the AuthenticationManager to a lazy approach"

This reverts commit 226eb4eded6aa098ad268edc8fba5ddec09b423b.

Conflicts:
	library/Icinga/Authentication/Manager.php

This fix is not appropriate

refs #5506
Fix PHP Fatal error:  Class 'Icinga\Authentication\Membership' not found in ManagerTest.php
The ErrorController must not require authentication
Decouple (automatic) preferences storage from user preferences (WIP)

DbStore, persisting preferences and tests not yet reworked.
Rework save preferences
Auth: Connect only when a authentication backend is used. Fix log in error messages

refs #5506
refs #5638
fixes #4931
Fixed executable flags on normal files.

Refs #5040
Fix executable flags on normal files

fixes #5040
Replace debug log with respecting log priorities

refs #5638
fixes #5522
Vagrant: Set up dev environment without any config file yet

refs #5638
resolves #5554
Vagrant: Fix public paths for the dev environment

refs #5638
refs #5554
Make Icinga Web 2 work without any config file

refs #5638
fixes #5523
Tests: Fix Fatal error: Class 'Icinga\Exception\NotReadableError' not found
Vagrant: Add authentication.ini and resources.ini to /etc/icingaweb

refs #5638
Temporarily ignore logged errors
TimeSince helper extended to support clientside support
Show exception in first header to ease JS support