ReactOS boot setup can not create and install on logical partitions

ReactOS boot setup can not create logical partitions and install ReactOS on it. This patch implements part of this functionallity. It can now create multiple logical partitions and install ReactOS, it will not boot though, as this needs another fix.
Known issues with this implementation:

• When creating multiple logical partitions and deleting them, setup will crash. Creating the partitions works as long as you create them straight ahead. (FIXED)
• ReactOS can be installed on a logical partition, but it will not boot it for now (needs a kernel change).
• There appears to be a problem with the partition table when creating logical partitions. When creating more than one logical partition and looking at them with i.e. linux gparted, it will report corrupted partitions. This problem is not visible inside ReactOS.
• When creating an extended partition you can not press ENTER to create the full partition as logical (or the remainder of the unpartitioned space). You need to create it by pressing 'L' and enter the size. (FIXED)