Only process changed entries

[bootsa]

Currently the postprocessing script (re)generates all the entries in entries.json when it is changed - which might not even affect the ouput, for instance an entry's updated last modified timestamp triggered by an edit in an a property that isn't used by the processor. Only changes to the output are saved through git.

This is a waste of processing and as the corpus grows will quickly become unmaitainable.

It might be possible to skip processing entries that haven't changed based on their last modified date stamp... but what happens when an associated entry (an author entity) is changed that doesn't specifically get reflected in the main entry's last modified datestamp (for instance a change to an author's given or family name properties)?

[bootsa]

Maybe #6 will help with this.