PARQUET-79: add a streaming Thrift API, to enable processing the metadata as we read it and skipping unnecessary fields.

This pull request provides an API to read thrift in a streaming fashion.
This enables ignoring fields that are not needed without loading them into memory.
It also aloow treating the data as it comes instead of when it's fully loaded in memory.

Author: julien <julien@twitter.com>

Closes #8 from julienledem/streaming_metadata and squashes the following commits:

621769a [julien] cleanup refactoring
a58913d [julien] rename add to consume
e5c78fc [julien] #simplify
cb386ce [julien] RIP TypedConsumerProvider, @tsdeng did not like you
8dd801e [julien] Merge branch 'master' into streaming_metadata
958726f [julien] javadoc; fix apis
9be786a [julien] added simple readMetaData method
bee937a [julien] refactor, cleanup
6368bdc [julien] streaming thrift reader
71c85de [julien] first stab