Macro based Scala APIs for Predicate and Projection push down

There has been some experiments with Scala macros to make Predicate and Projection APIs in Scala.
In particular by `[~neville]`:
https://github.com/nevillelyh/parquet-avro-extra/blob/master/parquet-avro-examples/src/main/scala/me/lyh/parquet/avro/examples/ExampleApp.scala
https://github.com/nevillelyh/parquet-avro-extra/commit/090f8d1d1d7d44489bb71e04465d4a12a46432c9#diff-89dca6adcdf105c6063661de43931c29R15

There have also been some discussion at Twitter.

**Reporter**: [Julien Le Dem](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=julienledem) / @julienledem

_{**Note**: *This issue was originally created as [PARQUET-218](https://issues.apache.org/jira/browse/PARQUET-218). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

Comienza leyendo el archivo parquet-avro-extra ExampleApp.scala enlazado y el commit referenciado; después, compara sus experimentos con macros de Scala con las API actuales de parquet-java. El issue estará completo cuando se haya acordado e implementado un enfoque definido basado en macros para el push down de Predicate y Projection.

Escrito por el modelo de indexación a partir del texto del issue.