Refactor Far::StencilTablesFactory

- re-implement the pool allocator
    - use templates to remove code redundancy between regular & limit stencils
    - leverage [] operator overloading to simplify stencil factorization
    - add the ability to treat subdivision levels independently (see below)

- refactor Far::TopologyRefiner::Interpolate<>() methods to pass buffers by reference
  (allows overloading of [] operator)

- rename some of the stencil factory options
- propagate changes to Osd / examples / tutorials...