Add PV with path to last master file

[ericonr]

FullFileName_RBV provides the full path to the last file written by saveTask. After an acquisition is completed, this will necessarily be a data file.

Would it be reasonable (and accepted in this repository) to add a LastMasterFileName_RBV or MasterFullFileName_RBV PV (I'm taking better names) with the full path of the last master file that's been downloaded, so users of the IOC can directly open that file and see the full acquisition results?

Or is it expected that users assemble the name of the master file using the path, pattern, and sequenceid on their own?

[jwlodek]

I'd be in favor of this, it seems like a small change but should make client implementations simpler.