support private buffer ignore list

[codygman]

I think I could use boring buffers if I also changed my buffer display format to include the full path, but it would be nice to say "don't update buffers in ~/journal" so others don't see "X is editing personal-journal.org`.

Or maybe a whitelist would be better for this type of thing.

[Mstrodl]

@codygman maybe you should just disable elcord-mode on those files yourself(?)

[Zulu-Inuoe]

Problem I see is that by disabling elcord entirely your 'time spent' value will reset back to 0, whereas they'd just like to not report those buffers