Big OpenLM/DCLM <-> AI2 PR # 1

[revbucket]

Lots of changes here (may be considered a refactor more than a PR, but will still require some heavy code reviews and discussion about which changes to keep/fold in).

Summary of changes:

• Added commands for bff and sysreq to get sense of how much memory a given BFF run will require
• Changed some defaults of arguments:
  • min-ngram/max-ngram now default to [20,20]
  • by default the bloom filter file is not saved (this can be specified)
  • annotations have been merged into a single argument
• progress bar present (but a no-progress-bar arg is also present)
• some more abstraction/functions to break things up and eventually not repeat code when I push the S3 PR
• added BOTH level removal type (some discussion about what this does in the RemoveType enum)
• Added some printouts with BFF sparsity, removal rates, time
• misc performance-y things, like parallel iteration in some places