Since "lei up" is more often useful than not and incurs neglible
overhead; enable --save by default and allow --no-save to work.
This also fixes a long-standing when overwriting --output
destinations with saved searches: dedupe data from previous
searches are reset and no longer influences the new (changed)
search, so results no longer go missing if two sequential
invocations of "lei q --save" point to the same --output.