• (kg) fixed bug in interaction between Logger::Level and Level::is_valid
  so that now you can do $logger->level('INFO') instead of just $INFO.
  
• (ms) Added logic for 'composite appenders'. Appenders can now be
  configured to relay messages to other appenders. Added
  Log::Log4perl::Appender::Synchronized, an appender guaranteeing
  atomic logging of messages via semaphores.
  
• (ms) Added basic substitution to PropertyConfigurator. Now you can
  define variables (like in "name=value") and subsequent patterns
  of "${name}" will be replaced by "value" in the configuration file.
  
• (kg) Followed Mike's lead and added variable substitution to the
  DOMConfigurator.
  
• (ms) Added Log::Log4perl::Appender::Socket as a simple Socket
  appender featuring connection recovery.