[tex-live] expl3 package: l3vers.dtx

[Karl Berry]

Hi Joseph,

    I've recently spotted that TeX Live misses out l3vers.dtx from 
    tex/latex/expl3. 

1. It is unprecedented to install a .dtx file in the runtime.
   I sincerely hope this is not really needed.

2. All TL is doing is copying the .tds.zip you provide.  If you want it
   in the runtime, fix it at your end :).

k