CHANGES

no exit listeners defined for appenders by default. users should call log4js.shutdown in their exit listeners.
context added to loggers (only logstash uses it so far)
logstash split into two appenders (udp and http)
no cwd, reload options in config
configure only by calling configure, no manual adding of appenders, etc
config format changed a lot, now need to define named appenders and at least one category
appender format changed, will break any non-core appenders (maybe create adapter?)
no replacement of console functions