added torrent_handle::set_download_limit() and fixed typo, thanks to spyhole for reporting

docs/manual.rst

@@ -334,7 +334,7 @@ remove_torrent()
 the tracker that we've stopped participating in the swarm.
 
 
-set_upload_rate_limit() set_downlad_rate_limit()
+set_upload_rate_limit() set_download_rate_limit()
 ------------------------------------------------
 
 	::

include/libtorrent/torrent_handle.hpp

@@ -185,6 +185,7 @@ namespace libtorrent
 		// abort the torrent.
 
 		void set_upload_limit(int limit);
+		void set_download_limit(int limit);
 
 		// manually connect a peer
 		void connect_peer(const address& adr) const;

src/torrent.cpp

@@ -921,7 +921,7 @@ namespace libtorrent
 		if (!have_all) return false;
 
 		hasher h;
-		h.update(&m_metadata[0], m_metadata.size());
+		h.update(&m_metadata[0], (int)m_metadata.size());
 		sha1_hash info_hash = h.final();
 
 		if (info_hash != m_torrent_file.info_hash())

src/torrent_handle.cpp

@@ -212,6 +212,16 @@ namespace libtorrent
 			, boost::bind(&torrent::set_upload_limit, _1, limit));
 	}
 
+	void torrent_handle::set_download_limit(int limit)
+	{
+		INVARIANT_CHECK;
+
+		assert(limit >= -1);
+
+		call_member<void>(m_ses, m_chk, m_info_hash
+			, boost::bind(&torrent::set_download_limit, _1, limit));
+	}
+
 	bool torrent_handle::is_paused() const
 	{
 		INVARIANT_CHECK;