[NDK]: Add OB_FLAG_KERNEL_EXCLUSIVE and OBJ_KERNEL_EXCLUSIVE flags

[NDK]: Add OB_FLAG_KERNEL_EXCLUSIVE and OBJ_KERNEL_EXCLUSIVE flags
[NTOSKRNL]: Add a helper function such that user-mode cannot pass certain kernel-only object attributes to ObOpenObjectByPointer.
[NTOSKRNL]: Make \Device\PhysicalMemory OBJ_KERNEL_EXCLUSIVE
[NTOSKRNL]: Deny access to user-mode when opening a handle to an object with OBJ_KERNEL_EXCLUSIVE
[NTOSKRNL]: Fix NtOpenProcess, NtOpenThread, NtOpenThreadTokenEx, NtOpenProcessTokenEx to use the helper function. Should fix Rtl using OBJ_KERNEL_HANDLE in user-mode.
Thanks to ThFabba for finding out these bugs, and the hbelusca for adding a missing check to NtOpenProcessTokenEx.

svn path=/trunk/; revision=69340