Merge the code in pv.c into pmap.c directly. Place all page mappings onto

Merge the code in pv.c into pmap.c directly.  Place all page mappings onto
the pv lists in the vm_page, even unmanaged kernel mappings.  This is so
that the virtual cachability of these mappings can be tracked when a page
is mapped to more than one virtual address.  All virtually cachable
mappings of a physical page must have the same virtual colour, or illegal
alises can be created in the data cache.  This is a bit tricky because we
still have to recognize managed and unmanaged mappings, even though they
are all on the pv lists.