onem2m-core module is too big and is dependent on too many modules which are not really related to core of the IoTDM.
E.g. implementations of protocol communicatio channels must be removed into own submodules.

It is important to separate APIs for plugins into standalone dependency so plugins will be dependent on the API and not on the implementation of onem2m-core and it's dependencies.
There are many problems in case of changes in internal implementation of onem2m-core and its dependencies, e.g.: migration to Karaf4 caused broken KarafFeatureLoader module, because plugins dependent on onem2m-core become dependent on some incompatible transitive dependencies (e.g.: Jetty 9 instead of Jetty 8). This is the reason why this bug is blocker since it blocks migration and stabilitzation of KarafFeatureLoader for Karaf4

It will be probably needed to implement register of provided communication channel implementations in the PluginManager, because current implementation is tightly coupled with onem2m-core and implementations of CommunicationChannels.