Line trimming in README.md
Debugging is now controlled per context

Config property: "debug" = "<context(,s)>"
Contexts: all,generic,broker,topic,metadata,producer,queue,msg

Usage:
  rd_kafka_conf_set(&conf, "debug", "topic,producer,...", ..);
Moved topic.metadata.refresh.interval.ms to global (not producer-specific) config.
Proper broker metadata refresh on leader failure. (issue #14)

Config property:
Config property: "topic.metadata.refresh.fast.cnt" (def 10)
Config property: "topic.metadata.refresh.fast.interval.ms" (def 250ms)v
Some locking fixes
Metadata triggered debug messages should be in metadata context.
Use CC rather than LD for linking

LDFLAGS is really meant to be passed to CC, not LD. The current code
fails e.g. with Debian's default LDFLAGS (-Wl,-z,relro).

Fix this by switching our Makefile to use CC for linking.
Update README.md with new URLs

Varnishkafka has a simpler github project name now. Also, the separate
librdkafka repository for Debian doesn't exist and it was merged with
this one, in a separate branch.
Avoid typedef redefinitions (issue #18)