Merge pull request #8 from inaka/master

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added support for requesting all topics by specifying an empty array
keeping track of the known topics and added a new function to request metadata
fixed a bug when killing broker connections
Merge pull request #9 from inaka/hernan.request_all_topics

Added functionality for requesting all topics
improved the handling of certain partition errors
Merge pull request #10 from inaka/hernan.request_all_topics

improved the handling of certain partition errors
fixed being forced to set a list of topics on the app config
Merge pull request #11 from inaka/hernan.fixed_topics_default

fixed being forced to set a list of topics on the app config
Merge pull request #6 from HernanRivasAcosta/master

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