I decided to whip up a quick module of my own from scratch this morning. https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff/blob/master/characterencodings.d
Example:
import arsd.characterencodings;
auto data = cast(immutable(ubyte)[])
std.file.read("my-windows-file.txt");
string utf8String = convertToUtf8(data, "windows-1252");
// utf8String can now be used
It doesn't do everything but it's a decent start.
