shared library loader (wrapper for GetProcAddress & Co)

[Andrej Mitrovic]

I don't think there are any, searching for GetProcAddress only returns
loader.d which seems to be an old module for loading executables but
probably unrelated to DLLs (?).

There's dll_helper.d in druntime\src\core\ but it only has some TLS
workaround features.

I've found some good solutions for loading DLLs in the Derelict and
DSFML projects though.