[RTL]: Fix a bug introduced Mon Dec 6 00:25:14 1999 UTC (10 years, 10 months ago...

[RTL]: Fix a bug introduced Mon Dec 6 00:25:14 1999 UTC (10 years, 10 months ago) in revision 828. NtFreeVirtualMemory takes a pointer to the address to free, not the address instead. For the last 11 years, freeing the process parameter block resulted in freeing whatever the first value in the structure is, which is MaximumLength and initialized to 0x1000. ReactOS would then free whatever random address was in that area. In real Windows, it is illegal to free an allocation in the middle of the base address, and this call failed with the new VAD code. ReactOS either leaked the memory or freed random data, who knows.
[RTL]: Make the PPB live in the Heap instead of having its own virtual allocation, fixing the issue above. Stop rounding it to a PAGE_SIZE, and just use the space required.

svn path=/trunk/; revision=49169