update file terminology in tools and docs
Reported by Huong Luu.
The command line utilities for Darshan often refer to files as either "shared" or "unique". It would be more correct to refer to them as "globally shared" or "non-globally shared" to reflect that Darshan only identifies shared files if all ranks open them.
This will require updates to several tools to fix. We also need to check if some tools identify partially shared files as a post processing step, which would be a third category.