Add a CLI command that deletes an LDAP config

With this change LDAP configurations can be managed completely from
the command line.
Migrate new app settings to AppFramework

Let's migrate those two new files.
rework getFileSize
small fix
ok; still some bugs that had to be fixed
bugfixes
small fix
adding missing email address for principal

* fix #8515
* add mail only if it exists
Pass the cached data to the filesystem watcher
also update shared watcher
Fix shared cache getFolderContents
Better reuse of cache data for getFolderContents
Properly catch 503 storage not available in getQuotaInfo

When doing a PROPFIND on the root and one of the mount points is not
available, the returned quota attributes will now be zero.

This fix prevents the expected exception to make the whole call fail.
Only mount the storages for the user once
On Windows platform we have no stable etag generation - yet
Make supported DBs configurable within config.php

This commit will make the supported DBs for installation configurable within config.php. By default the following databases are tested: "sqlite", "mysql", "pgsql". The reason behind this is that there might be instances where we want to prevent SQLite to be used by mistake.

To test this play around with the new configuration parameter "supportedDatabases".
code cleanup during review :+1:
Merge pull request #11786 from owncloud/MakeSupportedDBsConfigurable

Make supported DBs configurable within config.php
Merge pull request #11799 from owncloud/no-stable-etags-on-windows

On Windows platform we have no stable etag generation - yet
[tx-robot] updated from transifex