* Mostly aimed at removing Log/DatabaseEnv includes from other headers
* Fix most packet headers including other packet headers - moved common structures such as ItemInstance to their own files
* Moved SAI function definitions to source files (massive or requiring many different dependencies)
* benefits from empty optimization (objects are only constructed if needed).
* supports r-value references (move semantics) (boost >= 1.56.0).
* preparation for c++14/17's std::optional and std::none_t.
* add move constructor to CompactArray.