v5.2.8

Bug fixes:

• set_multi and delete_multi on more than one server retried forever, hanging the caller, when a server accepted their writes and then closed the connection before replying. Each quiet write reset the server's failure count, so it never reached socket_max_failures. Only a request whose reply is read resets it now, and the server is marked down and Dalli::NetworkError raised, as for get
• A signal arriving while Dalli::Compressor or Dalli::GzipCompressor was compressing or decompressing could make Ruby's zlib return before it had finished (ruby/zlib#49). Depending on the Ruby and zlib gem versions, that raised Zlib::BufError or Zlib::DataError, or stored a truncated value that later failed to decompress. Both compressors now keep finishing the stream until zlib reports its end. GzipCompressor no longer goes through GzipWriter and GzipReader, so it now always returns decompressed values as binary strings, as Compressor does (#1299)