[NTOSKRNL]: Properly respect the registry's Win32PrioritySeparation value instead...

[NTOSKRNL]: Properly respect the registry's Win32PrioritySeparation value instead of ignoring it.
[NTOSKRNL]: Actually apply the foreground priority boost to threads in a foreground process.
[NTOSKRNL]: Correctly handle the case where the quantum length and fixed/variable flag are set to "default", instead of falling back into the server case.
Thanks to WINSRV doing the right thing, ReactOS console apps now receive the priority separation boost. However, my tests show that it doesn't last as long as it should on Windows (quantums too short? bug in priority decrement?). Also, since Win32k.sys doesn't tell the kernel about foreground GUI apps, they don't get the boost. Someone needs to add a NtSetInformationProcess call in whatever win32k function determines active focus.
Dedicated to ThFabba who needs to write some tests ;-)

svn path=/trunk/; revision=69324