Clean examples/ on "make clean" too

examples are being built on "all" but not cleaned up on "clean". Treat
this similar to how tests/ is treated and cleanup after ourselves.
Fixed IRC channel and typo in README
Correctly handle IPv6 broker addresses added by application (issue #23)
Updated 0.8 status in README
Let produce API honour "message.max.bytes" (issue #24)

Producing a message larger than "message.max.bytes" will now make
rd_kafka_produce() return -1 and set errno to EMSGSIZE.
Producer msg count was increased if msg was too large (for issue #24)
0003-msgmaxsize: test case for message sizes (issue #24)
Fix uninitialized warning (gcc-4.4)
Dont re-query metadata immediately if leader was lost (issue #28)
Dont reuse broker ERR_REQUEST_TIMED_OUT if timeout was local.

Reusing the error code makes it harder to distinguish where the
timeout occured.
rdkafka_performance consumer: call poll to handle stats callbacks.
Added broker request RTT statistics
Reformatted stats JSON output not to contain arrays

All arrays have been converted to object maps to ease integration
with xpath named tools such as WMF's ganglia importer.

Example output:
https://gist.github.com/edenhill/7597127
Fix various compilation problems reported by debian build
Proper signed casting of protocol Strings and Bytes
printf off_t need casting for portability
Dont do int casts in pointers
kfreebsd-amd64 compilation fixes: msg_iovlen is not size_t
Merge pull request #30 from edenhill/debcompfix

Debcompfix
Fixed recursive locking on broker fail+buf retry (issue #27)