message: Add comments to orphanpool.h
diff: class CTxOrphanPool
  {
  private:
  - // Used in EraseOrphansByTime() to track when the last time was we checked the cache for anything to delete
  + //! Used in EraseOrphansByTime() to track when the last time was we checked the cache for anything to delete
  int64_t nLastOrphanCheck;
  public:
  - // Current in memory footprint of all txns in the orphan pool.
  + //! Current in memory footprint of all txns in the orphan pool.
  uint64_t nBytesOrphanPool;
  struct COrphanTx
  @@ -39,10 +39,19 @@ public:
  CTxOrphanPool();
  + //! Do we already have this orphan in the orphan pool
  bool AlreadyHaveOrphan(const uint256 &hash);
  +
  + //! Add a transaction to the orphan pool
  bool AddOrphanTx(const CTransaction &tx, NodeId peer);
  +
  + //! Erase an ophan tx from the orphan pool
  void EraseOrphanTx(uint256 hash);
  +
  + //! Expire old orphans from the orphan pool
  void EraseOrphansByTime();
  +
  + //! Limit the orphan pool size by either number of transactions or the max orphan pool size allowed.
  unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans, uint64_t nMaxBytes);
  };
  extern CTxOrphanPool orphanpool;
  