`--last` should not remove the header

[vincentdephily]

Shouldn't be too hard for tables with a single header line, but would be trickier for stats. Multi-header tables can probably be ignored for now, as they don't make use of --last anyway.

[vincentdephily]

Fixed for log. Stats don't support --last and I doubt it makes sense for them. predict is arguably affected, but it's Pid lines that get removed (not headers), which seems like the proper behavior.