scsynth: rearrange headers for msvc compatibility

we need to include the windows headers first to avoid IN/OUT name clash

Signed-off-by: Tim Blechmann <tim@klingt.org>
sclang: InitAlloc - cleanup weird win32 alignement code

Signed-off-by: Tim Blechmann <tim@klingt.org>
sclang: FileDelete - implement via boost::filesystem

Signed-off-by: Tim Blechmann <tim@klingt.org>