Make it possible to specify a test file to run instead of rake test as:

$ bundle exec ruby test/plugin/test_in_status.rb

In addition, we can specify a line number like:

$ bundle exec ruby test/plugin/test_in_status.rb --location 24
Add tag information to emit error log
Merge pull request #491 from fluent/unit-test-unit-run

Make it possible to specify a test file to run
Remove 1.8 support code from Fluent::Registry
Add register_xxx API to parser and formatter plugins
Merge pull request #495 from fluent/add-register-api-to-parser-and-formatter

Add register_xxx API to parser and formatter plugins
fixed bool_value and add test for Fluent::Config.size_value, time_value, bool_value
Merge pull request #477 from tatsu-yam/fix-bool_value

fixed bool_value
Add error stream API to EventRouter

With @ERROR, emitted events are routed to @ERROR label with warning message.
Without @ERROR, emitted events are dumpped in Fluentd's warning logs.
Use emit_error_event for each filter call
Add emit_error_event to RootAgentProxyWithoutErrorCollector