[upgrade] print update message before running the update code

* otherwise you don't know during which app update something failed

Accept this language change "at your own risk"

Make an assertion in risky test testGetNodeForPathRoot

Use trusted mimetype

Properly set mtime on S3 for touch operation

fix search for results only from subfolder

We shall not use untrusted mimetypes in this context

Send the mime icon if we can't generate a preview

emit hooks from a view as long as the path is inside the default root

Allow multiple whitespace in type hints in AppFramework

Workaround for empty dir deletion for SFTP

Use proper type

Type hints such as `@param bool     $doSomething` will now correctly get
parsed, allowing for alignment of docblock parameters if the app developer so
wishes.

This is a string

Add tool to check OCP for missing @since tag

[master] Verify if path exists

Fix naming of param in private/server.php

[config.sample.php] set correct default value for skeletondirectory

* gets executed in autotest.sh and fails if some PHPDoc is missing
* doesn't check classes/methods that are marked as @deprecated
* iterates over all .php files in lib/public

Only sort by group name when LDAP is involved

Acquire read lock when getting file or directory info

update the file cache within the write lock

Explicitly clear the stat cache after deleting an empty folder to make
sure it is properly detected as deleted in subsequent requests.

This works around a problem with phpseclib where the folder is properly
deleted remotely but the stat cache was not updated.