* Make the filtering better readable

* Add some more methods to the sensitive list

* \OC\DateTimeFormatter
* \OC\DateTimeZone
* \OC\ForbiddenException
* \OC\HTTPHelper
* \OC\HintException
* \OC\LargeFileHelper
* \OC\Log
* \OC\NaturalSort
* \OC\NavigationManager
* \OC\NeedsUpdateException
* \OC\NotSquareException

With PHP7 Throwable is the new base interface for all Exception and Error - we should be capable to log Throwable as well

Fixes https://github.com/owncloud/core/issues/23717

* fixed #16318
* create logException in ILogger
* add unit tests

 * Log condition for log level increase based on conditions. Once one of these
   conditions is met, the required log level is set to debug. This allows to
   debug specific requests, users or apps

 * Supported conditions (setting `log_condition` in `config.php`):
    - `shared_secret`: if a request parameter with the name `log_secret` is set to
                this value the condition is met
    - `users`:  if the current request is done by one of the specified users,
                this condition is met
    - `apps`:   if the log message is invoked by one of the specified apps,
                this condition is met
 * fix unit test and add app log condition test

* remove duplicate code from child classes

This reverts commit 6a1a4880.

This is a first draft. It has only been tested with the ownlcloud logger.
Some internal fields are JSON encoded several times which makes it harder to read.

Most of the normalizer is borrowed from Monolog
https://github.com/Seldaek/monolog/blob/master/src/Monolog/Formatter/NormalizerFormatter.php

- inject logger class into log
- adding PHPDoc comments and fixing typos

Conflicts:
	lib/private/vcategories.php

This is the other way around then it was.

OC\Log implements the Psr\Log\LoggerInterface interface. See
https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-3-logger-interface.md
for the full interface specification.