Refactor some file writing and reading logic:

- read “OQ” attr from structured SAMRecord field

  converting into and out of BAM using ADAM was dropping the “OQ”
  attr; HTSJDK puts it in its own field but ADAM was looking for it
  in the catch-all attributes field.

- style nits / long lines

- ADAMMain formatting

- apply predicate shorthand

- move adamBamLoad into ADAMContext

  I'm a little torn about this one, since I see the motivation for
  having AlignmentRecordContext own logic for things we know will be
  AlignmentRecords, but adamBamLoad also is called from and calls into
  (via implicit conversion from SparkContext back into ADAMContext)
  other things in ADAMContext that made it feel like a more natural
  fit inside of ADAMContext.

- factor out parquet-saving config

- factor multi-format saving out of Transform

- add helper for saving only aligned records

  a.k.a. BAM or ADAM records; no FASTQs
Merge pull request #450 from ryan-williams/saving

Refactor some file writing and reading logic