Alternative BigInt library

[zhukov]

I was looking for some alternative library to implement prime factorization. May be that could help on 1.1 for some reason.
@staltz has shown Forge crypto library. I've found, that it uses Tom Wu's jsbn BigInteger implementation (same as we use in Webogram). So no point in it.

I've found 3 options:

• http://www.leemon.com/crypto/BigInt.js
• https://github.com/vibornoff/asmcrypto.js/blob/master/src/bignum/bignum.js
• https://github.com/jtobey/javascript-bignum

According to this article, the first one is probably what we need:

this library provides the possibility to perform the operations directly on its values, which can make it a lot faster

The benchmark states that leemon library is also faster. So I think, we should give it a try and check results on different hardware/software.

[jimCresswell]

@zhukov @digitarald awesome, that is worth testing. As I understand it the underlying issue hasn't been identified yet. It may be to do with the number of assignments in the prime factor algorithm causing garbage collection to swamp the calculation but we'd really need to prove that before we tried acting on it.