Handle document links when journal re-name / delete

[cloverich]

After naively changing journal references from id to name, document links can be broken in two states:

• If a document references a journal, and the journal is re-named... need to update ALL links where documents link to it...
• Same thing if a journal is removed (well, in that case, dead links are probably... fine...)

Very hard to say what to do here... building the app behavior around the file system... so the app can be deleted... and avoid having to export... idk seems kind of like a lot of work to benefit an extreme minority of users; esp. when an export could serve the same purpose. Hmmmm.