[AS7-462] minor cleanup
get rid of boot module
layered object model
identity patch runner
new patching schemas and parsing/marchalling
update directory structure layout doc

move modules/bundles patch metadata below the .installation directory.
The system bundle/modules no longer contain any metadata relevant to an
installation
refactoring

* renamed commit/rollback operation to complete/cancel
* hide the installation of the patch info & installation manager
  services behind static helper methods in their respective classes
* fix patching XML 1.1 marshalling
* fix import of packages used only in Layer/AddOn/Identity javadoc
cleanup patch metadata
add layer test case

moved mkdir() method to IoUtils to ensure the directory hierarchy always
exists before writing cumulative and references files
fix class cast error
move each patch element contents in separate directories inside the
patch
fix rolling back a patched layer
fix layers misc files + add-ons
fix patch apply operation

* in LocalPatchOperationStepHandler, build a Patch Runner using the
installation manager service instead of patch info service.
* fix class cast exception in local patch operation handlers
added layer and add-on as child resources of patching
update metadata builders, extract layersConfig
patch generator wip
the root patch is actually the only owner for misc-files. It's up to the patch-gen tool to resolve eventual conflicts
fix patching tests
update rollback handling for modules