small cleanups.  StencilConvertAST now takes parameter for unroll factor of innermost loop.
small cleanups.  StencilConvertAST now takes parameter for unroll factor of innermost loop.

shoaibkamil/asp,mbdriscoll/asp-old,mbdriscoll/asp-old,richardxia/asp-multilevel-debug,richardxia/asp-multilevel-debug,mbdriscoll/asp-old,pbirsinger/aspNew,richardxia/asp-multilevel-debug,shoaibkamil/asp,pbirsinger/aspNew,shoaibkamil/asp,pbirsinger/aspNew,mbdriscoll/asp-old