attachDetach has problems

Functionality to add/problem to solve

1. attachDetach performs checking on local patch sizes instead of global sizes.
2. e.g. pimpleFoam does not recalculate Uf/Uf.oldTime()

Target audience

Topo changes.TJunctionTopoSwitching.tgz

potential fix (but recalculates whole flux): pimpleFoam.C