Defined APC_VIRTUAL_ALLOC and APC_VIRTUAL_FREE requests.

Based on a patch by Anatoly Lyutin.

user32: Remove redundant visibility checks of a maximized MDI child, add an explanation why we do that.

This reverts commit 6fb1869b.

Change HTTP_EncodeBasicAuth to convert the username and password into 
utf8 before base64 encoding.