_typeset doesn't list correct descriptions for functions -T

[Mikael Magnusson <mikachu@xxxxxxxxx>]

I noticed that functions -<tab produces this listing (and more),
-T  -- tie scalar to array or trace function
-t  -- turn on execution tracing for functions

But it should say
-T  -- trace execution of this function only

And the code in _typeset seems to try to do this. It is somewhat
obfuscated though, so I can't tell why tf works while Tf doesn't. I
additionally noticed this while checking stuff;
typeset -f +<tab>
_typeset:100: bad option: -f

And finally, functions +<tab> only lists +t, not +T. (Bonus points if
the messages change to "off" here).

--
Mikael Magnusson