On clone create a new instance of the Configuration

To avide effects on the original instance of Connection when the clone
is modified, for instance on authentication checks.
Use array_key_exists instead of isset, because the latter returns false if the assigned value is null
add test for cloning and keeping configuration seperate
Fix 'Undefined variable: message' in OCP\Util::logException
prevent dimmed ocdialog div from scrolling
Fixed mtime reading from OpenStack API

The API seems to return floating point values, which prevents
the hasUpdated() check to work and causes the scanner to rescan
everything every time.

Backport of fa00a18 from master
Fix swift touch operation

The touch() operation now uses "UpdateMetadata()" instead of "Update()"
which doesn't clear the object's contents.

This fixes syncing, as the sync client needs to use touch to update the
object's mtime.

Backport of 2a08e35 from master
Merge pull request #7901 from owncloud/fixed_position_ocdialogdim

prevent dimmed ocdialog div from scrolling
don't block php session while download is in progress
LDAP: Read email and quota when mapping user, fixes #7785
don't write file if opening a stream to encrypt the data fails
remove pl_PL - fixes #7973
Revert "remove Sabre_DAV_Browser_Plugin"

This reverts commit e4104e63d924c41e80a42282cce2a7e09ec36c42.
Merge pull request #7976 from owncloud/fix-7973-stable6-2

remove pl_PL - fixes #7973
Correction: failure on sharing when user ID was prefixed by zero

Backport of 51b727c from master
general styles for the content area
add PHP docs
more precise php doc
Fix admin-dir_permissions redirection when cannot write warning
is shown.
Merge pull request #7931 from owncloud/fix_7785_stable6

LDAP: Read email and quota when mapping user, fixes #7785