pagetable unification: this time for sure!

Here's a new set of patches. I've compiled tested:

* 32-bit PAE paravirt
* 32-bit non-PAE paravirt
* 32-bit PAE non-paravirt
* 32-bit non-PAE non-paravirt
* 64-bit

and test-booted them to usermode under kvm (though I'm currently typing this under 32-bit PAE paravirt).

The patches are based on linux-2.6-x86.git commit
022b7918fe3ac93ea171558e95d391efe82af4bb.

The net effect of these patches is little more than refactoring and code motion, though I wouldn't expect the generated code to be identical.

J