BCrypt code quality

[edjiang]

I'm not happy with the code quality of the BCrypt implementation I imported. This is one of the few BCrypt implementations in Swift (thanks @Joannis for porting @meanjoe45's Swift 1 implementation), so will have to do for now.

BCrypt is passing tests for now, so I'll clean up the API and punt on the decision to audit / improve the code quality myself, or wait for a more popular BCrypt library to pop up on Swift.

[edjiang]

Fixed up a lot of this in fb545e6 so the public API can be more stable, although the internals are still a bit messy. @Joannis might wanna check out the changes =]

[Joannis]

Will do!