Using the new completion system 'naked'

[DervishD <raul@pleyades.net>]

    Hello all :))

    I was wondering, while reading documentation about the new
completion system, two questions:

    - Will the old 'compctl' completion system disabled in the
future? And if the answer is 'yes', when?

    - Can I use the new completion system without compinstall'ing it
and without compinit'ing it, just by suitably calling compadd,
compset and compcall (no compdef...)?

    Yes, I know, those are strange questions, but I'm quite curious
about the inner works of the new completion system.

    Moreover, if the answer is not very large: what advantages gives
the new completion mechanism over the old one?

    Thanks a lot :)))
    Raúl