Remove (outdated) Octane/SunSpider variants to simplify distribution

[danleh]

@kmiller68 as discussed today: Could you prepare a list of Octane/SubSpider line items that might complicate distribution due to licensing? Once we have that, we can decide on a case-by-case basis, whether to remove them (ideally ending up with just MIT/BSD-licensed workloads).

[kmiller68]

It looks like the current list is:

Octane:
  box2d
  deltablue
  gbemu
  pdfjs[1]

SeaMonster:
  stanford-crypto-aes
  stanford-crypto-pbkdf2
  stanford-crypto-sha256
  sjlc.js[2]

SunSpider:
  base64[3]
  string-base64[3][4]

[1] seems like it's just the benchmark harness that's GPL and not the core bits: https://github.com/mozilla/pdf.js
[2] sjlc.js (the GPL part) seems dual licensed as BSD/GPL so presumably we'd just pick the BSD license.
[3] These are cross licensed as MPL 1.1/GPL 2.0/LGPL 2.1 so presumably we'd just pick the MPL license.
[4] This is only used by bomb-worker not the grouped SunSpider tests.

box2d and pdfjs's GPL bits appear to be copyrighted by Google so it might also be possible to redistribute those under a new license too.