Update to 16.0.1

Changelog:
    Fix setupcheck for intl module (server#15223)
    Take return of mkdir into consideration; photocache to not create a folder for deletion (server#15303)
    Remove the custom prefix from the table name length when checking on … (server#15312)
    Check if the data is in the lookup server (server#15341)
    Do NOT assume all files are selected if the first checkbox is (server#15345)
    Fix collapse button in app navigation in IE11 (server#15389)
    Make sure all middlewares are only registered once (server#15399)
    Allow to send the password of protected conversations (server#15405)
    Remove extra margin from warning messages in authenticate page (server#15409)
    Set Edge < 16 as incompatible with css vars (server#15417)
    Remove extra param in cache update call (server#15418)
    Handle 0 B default quota properly in the web UI (server#15424)
    Fix multiselect min width (server#15433)
    Make access column a real boolean (server#15434)
    Fix public upload by also load the semaphore method (server#15439)
    Remove setup args from logging (server#15442)
    Use non-absolute logout URL to fix wrong URL in reverse proxy scenario (server#15452)
    Fix mobile vertical scrolling (server#15469)
    Remove recommendation for opcache on CLI (server#15471)
    Update file-upload.js (server#15482)
    Add interfaces to interact with subscription from support app (server#15513)
    Fall back to application/octet-stream instead of using an invalid mim… (activity#374)
    Only call setViewerMode if FileList is available (files_pdfviewer#132)
    Use correct CSS URL, remove default marked settings and change to GFM rendering (files_texteditor#150)
    Use correct method to determine if HTTPS is used (firstrunwizard#189)

(ryoon)