std.typecons.Proxy needs to import std.traits.isArray

... because it is a mixin template which is evaluated at the place of
instantiation, where isArray is likely not available.
Make std.file.timeLastModified safe
Remove void initializers
Merge pull request #2463 from schuetzm/fix-proxy-traits-isarray

std.typecons.Proxy needs to import std.traits.isArray
Merge pull request #2466 from tom-tan/safe-file-timeLastModified

Make std.file.timeLastModified(in char[]) safe