Let's just use '/' as we do almost everywhere - this change fixes two failing unit tests
[Fixing Updater Unit Tests on Windows]
using $internalPath within call to self::correctFolder() because $path inside of it is not processed properly due to directory separator on Windows.
error logging has been added  in case the given 4path is not found within self::correctFolder
[Fixing Updater Unit Tests on Windows]
using $internalPath within call to self::correctFolder() because $path inside of it is not processed properly due to directory separator on Windows.
[Fixing unit tests in Windows]
on windows open resources will be locked while the stream is open.
closing the resource allows deletion below
Add tests for the updater with mount points
restore Updater functionality on non-Windows platforms
dirname('/test.txt') returns '\' on windows whereas on linux we get back '.'
Merge pull request #3661 from owncloud/fixing-windows-server-master

Fixing windows server master