merged RC_1_1 into master

ChangeLog

@@ -88,6 +88,7 @@
 	* resume data no longer has timestamps of files
 	* require C++11 to build libtorrent
 
+	* fix redundant flushes of partfile metadata
 	* add option to ignore min-interval from trackers on force-reannounce
 	* raise default setting for active_limit
 	* fall back to copy+remove if rename_file fails

src/part_file.cpp

@@ -397,5 +397,7 @@ namespace libtorrent {
 		std::memset(ptr, 0, std::size_t(m_header_size - (ptr - header.data())));
 		iovec_t b = header;
 		m_file->writev(0, b, ec);
+		if (ec) return;
+		m_dirty_metadata = false;
 	}
 }