[core] work around a Windows bug that may render a disk inaccessible on cleanup

* The root of the issue is that Windows IOCTL_DISK_CREATE_DISK does not properly
  zero all of the MBR/GPT/PBR structure with PARTITION_STYLE_RAW (which is what
  diskpart uses to clean a disk), and leaves plenty of partition artefacts behind.
* This means that, when an image with complex partitioning has been applied, such
  as Chromium/ChromeOS, you may end up with a drive that can not be repartitioned
  or reformatted in Windows (and this is completely independent of whether Rufus
  was used to perform these operations - For instance you will get the same issue
  if you use Win32DiskImager and diskpart + clean).
* The only option left for users then is to reset/repartition their drives in Linux
  or some other OS, as Windows' VDS becomes incapacitated to handle the drive, as
  the problem persists independently of reset/re-plug/Windows platform being used.
* To work around this, we ensure that we zero the MBR/GPT/PBR sectors BEFORE calling
  IOCTL_DISK_CREATE_DISK.
* Also move zeroing of the drive before partition reset.
* Closes #759

src/drive.c

@@ -1247,8 +1247,8 @@ BOOL RefreshDriveLayout(HANDLE hDrive)
 	return r;
 }
 
-/* Delete the disk partition table */
-BOOL DeletePartitions(HANDLE hDrive)
+/* Initialize disk for partitioning */
+BOOL InitializeDisk(HANDLE hDrive)
 {
 	BOOL r;
 	DWORD size;