Avoid to remove "threads" option in storaged configuration file with
rozo manager.
Avoid to remove "nbcores" option in storaged and exportd configuration
files with rozo manager.
Avoid to remove "storio" option in storaged configuration file with rozo
manager.
Avoid to remove specific "layout" option for one volume in exportd
configuration file with rozo manager.
Merge branch 'develop' of https://github.com/rozofs/rozofs into develop