Allows to inject something into the default content policy. This is for
example useful when you're injecting Javascript code into a view belonging
to another controller and cannot modify its Content-Security-Policy itself.
Note that the adjustment is only applied to applications that use AppFramework
controllers.
To use this from your `app.php` use `\OC::$server->getContentSecurityPolicyManager()->addDefaultPolicy($policy)`,
$policy has to be of type `\OCP\AppFramework\Http\ContentSecurityPolicy`.
To test this add something like the following into an `app.php` of any enabled app:
```
$manager = \OC::$server->getContentSecurityPolicyManager();
$policy = new \OCP\AppFramework\Http\ContentSecurityPolicy(false);
$policy->addAllowedFrameDomain('asdf');
$policy->addAllowedScriptDomain('yolo.com');
$policy->allowInlineScript(false);
$manager->addDefaultPolicy($policy);
$policy = new \OCP\AppFramework\Http\ContentSecurityPolicy(false);
$policy->addAllowedFontDomain('yolo.com');
$manager->addDefaultPolicy($policy);
$policy = new \OCP\AppFramework\Http\ContentSecurityPolicy(false);
$policy->addAllowedFrameDomain('banana.com');
$manager->addDefaultPolicy($policy);
```
If you now open the files app the policy should be:
```
Content-Security-Policy:default-src 'none';script-src yolo.com 'self' 'unsafe-eval';style-src 'self' 'unsafe-inline';img-src 'self' data: blob:;font-src yolo.com 'self';connect-src 'self';media-src 'self';frame-src asdf banana.com 'self'
```
Added config.php option to replace the default implementation of system
tag manager and system tag object mapper.
Also adjusted the comments manager factory to inject the server container
register CommentsManager service, allow override, document in config.sample.php
don't insert autoincrement ids in tests, because of dislikes from oracle and pgsql
specify timezone in null date
only accepts strings for ID parameter that can be converted to int
replace forgotten hardcoded IDs in tests
react on deleted users
react on file deletion
Postgresql compatibility
lastInsertId needs *PREFIX* with the table name
do not listen for file deletion, because it is not reliable (trashbin, external storages)
add runtime cache for comments
* Register OCP\Capability\IManager at DIContainer
* Add register capabilities to appframework
* Register capabilities in DI way
* Make unit test pass again
* Remove CapabiltiesManager from OCP
* This should allow the capabilities to be intergrated into the
appframework
* Unit tests
* Throw exception if closure does not return ICapability instance
