- Moved most the initialization of the pdcp_entity to the header.
- Initilize some variables in gtpu_ntoa.
- Removed debug print.
- Format eNB GTP-u debugging code.
this fixes the issue when the stack is torn down if, for example,
the radio couldn't be loaded correctly. it will hence call stop() on all stack
components which are not initialzized yet, and logging therefore doesn't work.
the log object is know during contruction time and therefore can be passed
in as soon as possible.