Fix XFailed test x86stdcall

There was a syntax error because the `extern "stdcall"` was outside the module instead of inside it.

* moved `extern` inside module
* change `extern "stdcall"` to `extern "system"`
* change `cfg(target_os="win32")` to `cfg(windows)`
* updated copyright dates
* changed log(error, ...) => info!(....)
* added `pub` keyword to kernel32 functions