[core] Implemented a new sender buffer.

[ethouris]

The new sender buffer is based on std::deque container, utilizes memory blocks handled by BufferedMessageStorage and the loss schedule is handled on top of the existing cells as linked list of flagged elements.

Changes:

• More reworks for comment removal and updated developer documentation
• closeAllSockets is blocked all logging (may be called as a part of global destructor and have logging system destroyed)
• Reworks in the receiver buffer, added walkEntries , removed m_BytesCountLock, improved performance in incPos
• Removed enterCS/leaveCS, they were always aliases to lock/unlock
• Moved encryption action to the function adding a packet to the buffer, not to happen when sending a unique packet
• Removed all portability-dependent uses of printf-like calls
• Removed previously added common snd loss management for groups (will be reinstated with common sender buffer).