Add option to disable summary metadata aggregation after MR jobs

[asfimport]

The summary metadata flies produced at the end of MR jobs aren't required for the job to complete successfully or for reading the data, so this should be an optional step in the MR commit phase. I'd like to add a property parquet.enable.summary-metadata that turns this off if set to false. The default will be true / enabled to match the current behavior.

Reporter: Ryan Blue / @rdblue
Assignee: Ryan Blue / @rdblue

_{Note: This issue was originally created as PARQUET-107. Please see the migration documentation for further details.}

[asfimport]

Julien Le Dem / @julienledem:
resolved by https://github.com/apache/incubator-parquet-mr/pull/68

apache/incubator-parquet-mr@be1222e