Add macros for declaring pipelines "files" in code
Add macros for declaring pipelines "files" in code

mathstuf/sprokit,mathstuf/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,linus-sherrill/sprokit,linus-sherrill/sprokit,mathstuf/sprokit,Kitware/sprokit,Kitware/sprokit,linus-sherrill/sprokit,Kitware/sprokit,Kitware/sprokit