... as a preparation for splitting up class AudacityProject.
Use ProjectWindow as an alias for AudacityProject, and fetch it from the
project with a static member function, where certain of its services are used;
pretending they are not the same class.
Use global accessor functions to get wxFrame from the project where only
wxFrame's member functions are needed, so there will be less dependency on
ProjectWindow when it becomes a distinct class.
... not member functions of AudacityProject
This puts DirManager.cpp and four others back into the big strongly connected
component of link dependencies. They will break out again when Project.cpp
becomes a low-level file.
Paul Licameli