Utils/Logger: Add some internal implementation documentation concerning SENF_LOG_CLASS_AREA()

Utils/Logger: Renoame all 'SENF_LOG_DEF_*' macros to 'SENF_LOG_DEFINE_*'
Utils/Logger: Add documentation on default compile-time limit

Socket/Protocols/INet: Fix INet6SocketAddress base classes

Packets: change *_RO field helper macros to add a private r/w accessor
senfscons: Introduce TEST_EXTRA_LIBS variable and move BOOSTFSLIB there
Socket/Protocols/INet: Make INet[46]MulticastSocketProtocol inherit MulticastSocketprotocol
Change SENF_NO_DEBUG to SENF_DEBUG

- some documentation updates, once again

doclib: Introduce an intermediate doxygen-compatible image map format
Update all image maps to the new format

Packets/DefaultBundle/extra_tests: use unittest include from utils /grrr
Socket/Protocols/AddressExceptions: fixes
Socket: fixed documentation

Socket/Protocols: Move incorrectly placed members from AddressableBSDSocketProtocol to BSDSocketProtocol
Socket/Protocols: Add missing DatagramSocketProtocol to some protocols
Socket/Protocols: Extend documentation of addressing classes

Changed all exceptions to inherit from senf::Exception
Replaced all throwErrno() calls with throw SystemException()

Examples/Sniffer: Dump all packet registries before starting the packet capture