Since Kaylee now supports Python plugins that can do arbitrary things
with spoken words, the pass_words option for shell commands seems
somewhat less necessary than before.  I never liked it in the first
place, because it was all-or-nothing: there was no non-hackish way to
pass the spoken words to only specific commands.  If I ever see a
compelling reason for this feature to come back, it may be
re-implemented in the form of a second shell plugin that passes words to
its commands.