- v4.74 released

- removed split sections from oem examples, use the kiwi
default split section for this examples

- changed the filesystem type to ext3 for 11.2 oem example
because we found issues with ext4 on 11.2

- fixed __addDefaultSplitNode() function. A cloneNode() call
is required if you add children from another DOM tree

- speedup prepare step with caches by skipping the bootstrap
installation. If there is a cache available we add the
bootstrap packages into the image package section and run
the rest of the installation procedure in one image
installation step

- make use of zypper's autorefresh feature and don't call
zypper refresh manually anymore