[NTOS]: Handle memory allocation failures correctly, supporting all the required...

[NTOS]: Handle memory allocation failures correctly, supporting all the required debug and caller flags (such as RAISE_ON_FAILURE). We no longer simply just return "NULL" in failure cases.
[NTOS]: Implement counters for paged and nonpaged pool. First-stage setup now shows Kernel Pool values again, as does Task Manager. Fixes the regression introduced when pool/non-paged pool was no longer managed through "memory consumer" API.
[NTOS]: Add more debugging paths and flags that were sent over from the "Aleksey Pool Patch". Most of them are not implemented.
[NTOS]: Fix a missing case when a pool header check was not being done.
[NTOS]: Check IRQL levels during pool allocation and free.
With tags and the counters, pool leaks should be massively more debuggable now.

svn path=/trunk/; revision=55879