Added "log_cb", and "log_level" configuration properties.
Added dr_msg_cb()

This feature is experimental and not all fields are set in the message.
Topic state debugging
Added rd_kafka_opaque() to return the opaque pointer set by set_opaque
Added note on stats_cb to rd_kafka_poll() documentation
Initial C++ interface for review
Updated symbols test with new symbols
Link rdkafka_example_cpp with -lstdc++
Reorg rdkafka.h to avoid typedef redefinitions (llvm error)
Added socket_cb and open_cb config properties (issue #77)

Allows racefree CLOEXEC implementations on non-Linux platforms.
Integrated mklove configure
Updated travis-ci to use configure
Updated travis-ci to use configure
Use portable -E option to sed
mklove update
Updated mklove
Proper linking (for Cygwin, ..)
Use platform specific symdumper (issue #79)
Updated mklove
Clarified comment on symdumper