TickDuration deprecation

[Walter Bright]

On 11/22/2017 1:41 AM, Timon Gehr wrote:
> Why would the conversion function be linked in if I never use it?

Good question. It depends on how the code is written, and how the compiler 
represents it in the object file, and how the linker deals with unreferenced 
parts of object files.

`format`, for example, dynamically decides whether to use floating point or not, 
so it is always linked in.