tabs -> 4 spaces in pom.xml
Update to slf4j 1.7.7
Add slf4j-simple dependency for tests
Only start/stop MessageReaders if MessageSource is already running
End of stream should log as debug, not warning
Enable debug logging in tests
Add simple test for MessageSource
Introduce Address class to encapsulate stream ID and feature ID
Register MessageSourceListeners by Address, not by stream ID
Add tests for adding/removing listeners
DRY up MessageSourceTest
Add Arduino class to combine MessageStream and FeatureRepository in tests
Rework Queue streams to block when reading, instead of returning -1
Avoid duplicate apostrophes in log message
Add custom assertion messages for easier debugging
Extract starting/stopping of MessageReaders into startUp/shutDown methods

This removes a race condition when starting MessageSource and adding
streams concurrently
Add test for removing streams from running MessageSource
Add read() method that takes a timeout
Avoid duplicate apostrophes in log message