push: move local lock logic in pushoperation During push, we try to lock the local repo to move local phase according to what we saw/pushed on the remote repo. Locking the repo may fail, in that case we let the push proceed without local phase movement (printing warning). This mean we have code in phase synchronisation that will check if the local repo is locked or not. we need to move this information in the push object to be able to extract the phase synchronisation in its own function. This is done as a boolean because putting reference to the actual lock outside of the main function sounded a bad idea.

push: move obsolescence related message into _pushobsolescence function No good reason to have them in the main fonction.

push: drop now outdated comment This `_pushobsolete` now exist for modularity purpose.

push: feed pushoperation object to _pushobsolete function This will allow the obsolete marker synchronisation to have full information on the ongoing push and pass information to other operation.