Use proper .dylib install_name on OSX
OSX requires linking required libs when creating dylib (issue #161)
Added buildbox.io build script
debug=queue now shows fetch queue info
rdkafka_performance: added latency measurement mode (-l) and offset reporting (-O)
If RD_KAFKA_OFFSET_TAIL() rewinds past offset 0, cap it to 0.
Interrupt all threads on rd_kafka_destroy() to quickly terminate

This avoids the slow termination due to waiting for various timeouts
in the threads.
Added "internal.termination.signal" property  (default off)

This enables quick termination by cancelling IO threads with signals.
Added quick termination to rdkafka_example and rdkafka_performance
Make sure to store EOF offset on termination (issue #164)
Updated copyright year in README