[wininet] Add InternetReadFileEx*

[Dmitry Timoshkov]

"Brian Gerst" <bgerst at didntduck.org> wrote:

> This patch implements the InternetReadFileExA and InternetReadFileExW 
> functions.  I don't know if this completely implements it to MSDN specs 
> (which are fairly vague), but it is enough to allow World of Warcraft to 
> read and display the server status message.

It would be much better instead of duplicating code implement InternetReadFile
via InternetReadFileEx.

-- 
Dmitry.