Bring wanassign back from the bit rot abyss. Three changes.
* Remove all of the code that dealt with allocating unconnected nodes. It used to be assign_wrapper passed all widearea node allocation decisions to wanassign, those in links and those that were unconnected. assign_wrapper now handles all unconnected nodes since assign is much better with features/desires and node type stuff. * Do not modify any database state in wanassign; It used to do the actual nalloc calls, but now it just returns the mapping to assign_wrapper so that we can more easily track "recoverability" and because there is existing code in assign_wrapper to allocate vnodes on the selected pnodes. No point in duplication. * Switch from mapping to vnodes, to mapping to pnodes. We made this change for other virtual nodes; instead of "fixing" to a vnode on a pnode, fix to the pnode. The resulting mappings are also given as pnodes, and assign_wrapper does the allocation on those selected nodes. Now all we need is uptodate widearea data!