ScalarArithmetic

When I integrated [ScalarArithmetic][scalar] and swift-complex in [my project][swix], compile issues were produced. This pull request changes the lines that produced the errors to constants (copy-pasted from Wolfram), which let me compile.

```swift
var x:Double = e
println(log(e)) # 1.0
println(sqrt(e)) # 1.64872127070013
```

[scalar]:https://github.com/seivan/ScalarArithmetic
[swix]:https://github.com/scottsievert/swix