Old Firefox and Thunderbird versions

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

Hi all,
is there a good reason for keeping the old Firefox and Thunderbird
versions around? I can understand keeping Firefox 24 as LTS release,
but is there a pointer in keeping anything older? Similary for
Thunderbird, why keep v10 and v17? They all are non-trivial in size and
build time. Note that older versions of xulrunner are a somewhat
different deal.

Joerg