Copy Etag header to OC-Etag for sabre calls

adjust controls bar width to not overlay scrollbar

Don't append user in a filtered list if groups don't match

Merge pull request #15225 from owncloud/make-setups-for-users-that-tend-to-use-owncloud-on-not-proper-machines-a-little-bit-more-secure

Add some generic default headers as well via PHP

Filter potential dangerous characters in path name

fine-tuning the empty content messages

Fix namespace for repair step tests

More elaborate command description for upgrade

We should not allow / or \ in the postfix here.

Keep the extension in temp files

always fall back to default share folder

Mount options GUI for external storage

Don't use placeholder for password in IE8 & 9

Fix share permission checks

Serve all files with a Content-Disposition of 'attachment' via WebDAV

Replace share proxy with a hook

core part of encryption 2.0

Remove IDE autocomplete fail

no php execution timeout for webdav

Ignore empty plurals just like with singulars

* the placeholder is in IE 8 and 9 just set as text and
  styled a bit grey. If the form is then serialized without
  typing something in the placeholder is sent as value
* this fixes that behaviour for the password field and
  properly detects empyt passwords
* fixes #14912

As an additional security hardening it's sensible to serve these files with a Content-Disposition of 'attachment'. Currently they are served 'inline' and get a "secure mimetype" assigned in case of potential dangerous files.

To test this change ensure that:

- [ ] Syncing with the Desktop client still works
- [ ] Syncing with the Android client still works
- [ ] Syncing with the iOS client still works

I verified that the 1.8 OS X and iOS client still work with this change.

expire versions in a background command