LuceneLogger.search returns Multimap<String, Map<String,String>>

Each key of a multimap denotes a message type.
And each message type contains documents.
Each document is Map<String, String>
Specify character encoding for 0MQ messages.
LuceneLoggerTest sleeps for 3 seconds for all messages to be logged.
LuceneLogger : Insert an empty line for readability
LuceneLogger.search now returns user-friendly search results.
protocol : time is now in milliseconds instead of seconds
Ignore /irclog*
Remove unused imports from LuceneLoggerTest
Don't remove test log data after LuceneLoggerTest is run