Add a unified and optionally more constrained API for expressing filters on columns

This is a re-opened version of:
https://github.com/Parquet/parquet-mr/pull/412

The idea behind this pull request is to add a way to express filters on columns using DSL that allows parquet visibility into what is being filtered and how. This visibility will allow us to make optimizations at read time, the biggest one being filtering entire row groups or pages of records without even reading them based on the statistics / metadata that is stored along with each row group or page.

Included in this api are interfaces for user defined predicates, which must operate at the value level by may opt in to operating at the row group / page level as well. This should make this new API a superset of the `parquet.filter` package. This new api will need to be reconciled with the column filters currently in the `parquet.filter` package, but I wanted to get feedback on this first.

A limitation in both this api and the old one is that you can't do cross-column filters, eg: columX > columnY.
One sort of pedantic question (let's be pedantic!) is just around the purpose that equality is meant to serve here. Is it purely to see if two trees are physically identical? Might be useful to have "logical" equality that we can use for testing and whatnot. Basically, logical equality is "are these filters LOGICALLY equivalent" rather than structurally...though that may not be decidable. Perhaps "do our optimizations reduce these two filters to structurally equivalent trees" ? ok enough pedantry