Major Description
fmeschbe had a look at the oak api and spotted the following problem:
Root#commit(String, CommitHook)
But the CommitHook interface is not part of the OAK API. we quickly searched for usages and found that this is only used for the Item#save case in oak-jcr to assert that the set of modifications is contained with the subtree defined by the specified target item.
IMO we should get rid of the flavour of Root#commit again and solve the Item-save issue differently. For example we could change it to Root#commit(String, String absPath) where the absPath would be the path of the target item...