MessageDirector: Add unit test for multiple post recieve.
MessageDirector: Implement multi POST_REMOVE.
Merge pull request #50 from OpenOTP/kestred

Multiple post remove
Code-cleaning: Remove extra indents in class declarations.
MessageDirector: Standardize passing of Datagrams to always use references.
Datagram: Fix memory leak.
MDParticipant: Add control message helper functions (like existing) for clarity and simplicity.
MDParticipant: Add spam log message to clear_post_remove
MessageDirector: Reorder handle datagram to (participant, data) to be consistent with other calls.
MDParticipant: Add last helper function for logger (all helpers are inline btw).
Amendment: Fixed logger return type.
MDParticipant: Moved member fields to "protected" and made them more cleanly accessible as more inline functions.
MessageDirector.cpp: Space/tab cleanup.
MDParticipant: Clean up variables and function declares.
MDParticipant: Remove unused bool return from handle_datagram.
code-cleanup: Move comment that was not properly migrated with previous branch.
compile-warnings: fix warning for core/config.h
compile-warnings: fix warnings for MessageDirector.h
compile-warnings: fix warnings for core/logger.h
compile-warnings: Fix warning for NetworkClient.h
ParticipantTest: Fixes compilation