Add support for UTF-16 strings for LowPaths in FS:USER

Nitpick, but I suggest getting into the habit of: `0 != src_bytes` for truth statements such as this. The reason is because if you (or someone else) makes a typo with your code such as `src_bytes =0`, that will evaluate as `true` and is easily overlooked. OTH, the compiler will flag the similar typo `0 = src_bytes` as a syntax error.