On Windows platforms code was added to zero-fill each newly allocated data file in order to work around Windows KB http://support.microsoft.com/kb/2731284. The KB only applies for Windows 7 and Windows 2008 Server installations, so there is no need to do it on each and every system.

This fix restricts the zeroing-out code to only versions, which have had the bug. It will not check whether the hot fix has been installed.
Revert "On Windows platforms code was added to zero-fill each newly allocated data file in order to work around Windows KB http://support.microsoft.com/kb/2731284. The KB only applies for Windows 7 and Windows 2008 Server installations, so there is no need to do it on each and every system."

Breaks Windows build, because VersionHelpers.h is not present with the VC10 compiler/SDK, which we use.

This reverts commit c4c0f3b6b849deba4b6ebb31ab13b0b26b626c55.
Merge remote-tracking branch 'upstream/master'