make sure preview prop is instanceof OC_Image before using it in showPreview

adding 'smallint unsigned' to type mapping for sqlite

Throw error in showPreview instead the constructor

fix typo. closes #11132

Use select2 for the groups excluded from sharing in admin page

[encryption] create backup from all keys before recovery

Match more URL fragments

Move BasicAuth check to isLoggedIn

This function is also used in a way such as:

```
	$preview = new \OC\Preview(\OC_User::getUser(), 'files');
	$info = \OC\Files\Filesystem::getFileInfo($file);
	if (!$always and !$preview->isAvailable($info)) {
		\OC_Response::setStatus(404);
	} else {
		$preview->setFile($file);
		$preview->setMaxX($maxX);
		$preview->setMaxY($maxY);
		$preview->setScalingUp($scalingUp);
		$preview->setKeepAspect($keepAspect);
	}
```

Which won't work anymore since `setFile` is used instead of passing the file in the constructor. Fixes a regression in master.

Resolves cache tests failing if the directory length is longer than 64

Remove old upgrade routines

Prevent updates between multiple major versions

Introduce cross-db ILIKE

Fixes https://github.com/owncloud/core/pull/11009#issuecomment-56103341

update encryption doc link

I don't know how we missed to update this :/

update ldap doc link

Ref https://github.com/owncloud/core/issues/11078

Ensures that Basic Auth works properly for APIs and removes the need for some even uglier lines of code.

Remove unused and overflowing function

Move basic auth check

Resolves https://github.com/owncloud/core/issues/10991 failure 4

Make 404 page easier to understand

force loading of encryption app to show correct error

Error needs to push body-id for new guest layout

Fixes https://github.com/owncloud/core/issues/11133

Tentative fix for legacy file actions unit test side effect