IO: Renamed update/rename elements
Merge branch 'master' into EZP-23328-io_interfaces_split

Conflicts:
	eZ/Publish/Core/IO/Handler.php
	eZ/Publish/Core/IO/Handler/Dispatcher.php
	eZ/Publish/Core/IO/Handler/Filesystem.php
	eZ/Publish/Core/IO/Handler/Legacy.php
	eZ/Publish/Core/IO/IOService.php
	eZ/Publish/Core/IO/Tests/Handler/Base.php
	eZ/Publish/Core/IO/Tests/Handler/DispatcherTest.php
	eZ/Publish/Core/IO/Tests/Handler/FilesystemTest.php
IO: Fixed Image SPI integ test
IO: Fixed IO root dir in integ tests

Both API & SPI will now use a temporary folder as $rootDir.

Testing of existence of files has also been made more accurate.
IO: Cleaned up IO fieldtype services