Allow process name to be overridden by log() argument

[bcg]

Not a very standard syslog client API feature, but we like divide up a lot specialized logs by the process name field. This keeps us from having to create a lot of unnecessary connection objects. Would you consider merging this so that we can continue to use your NPM packages? Thanks for the consideration!

[jurniman]

 var request_logger = syslog.createClient(514, 'localhost', {name: 'http'})
 , db_logger = syslog.createClient(514, 'localhost', {name: 'db'})
 , api_logger = syslog.createClient(514, 'localhost', {name: 'api'});

Thanks @bcg, used your pull to start with and ended up with above approach to manage it now.