VS2010 build: revert le256todouble() cast/ref/deref change.

Introduced by commit 87e5f35745321132cea3e5b21ddb7d69e8a8eb0f

The cast/ref/deref is performed wrong and breaks share/best share display.
It is not the value of target that should be increased, but its address.

If all else fails, add an `#ifdef _MSVC_VER`; we should avoid it if possible.

In either case, constructs like `&(*(((uint64_t *)target) + 24))` must be
explained (in a comment).