[IE9] Don't send link share password placeholder

Improve settings/apps page

When exiting the password field in the share dialog, IE9 would
mistakenly think that the password has changed and would send the
placeholder.

This fix prevents changing the password whenever the placeholder is set
as value.

Store list of apps which cannot be disabled in shipped.json

Generate author file by license.php build script

Fix #15651

Fix share link focus on click

Introduced the new webdav endpoint remote.php/dav holding the princip…

Add tests for Sabre Auth plugin + make getCurrentUser compatible

Clicking on the link share must focus and select it

Bump 3rdparty for phpseclib-2.0.0

Remove dead code from autoloader

Ensure the password is only hashed in case it's changed on the client…

Use optimized autoloader for files_external

Those variables are never written to. Thus this is dead code which should be removed.

Add HackerOne page to CONTRIBUTING.md

Use optimized autoloader for 3rdparty