Set overwritewebroot when installing owncloud to avoid problems

Fix #10514
Merge pull request #10929 from owncloud/issue/10514

Set overwritewebroot when installing owncloud to avoid problems
requesttoken has now a length of 30 chars
Fix method name
Merge pull request #10990 from owncloud/fix-testCallRegister-master

requesttoken has now a length of 30 chars
Create .user.ini for PHP-FPM

PHP-FPM can't read .htaccess PHP settings unless a PECL extension is installed.
From version 5.3+ of PHP, settings can be set in .user.ini files

This is a .user.ini file mirroring what is included in the .htaccess file
TODO: Update the documentation if there are sections documenting how to change some PHP limits
Merge pull request #10988 from owncloud/usetransactions-wrong-name

Fix method name useTransactions
Merge pull request #10992 from oparoz/patch-3

Create .user.ini for PHP-FPM
Reuse known fileids in the scanner
Cast mtimes to int
Reuse cache data of existing files during scan
Cast size to int
Reuse known cached data of folders