New elldata package minor update (updated generators)

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

Dear PARI users,

I have made a minor update to the elldata package.
The list of curves are strictly identical to the previous version, only the
generating set given by ellgenerators() is different for some curves. 

In particular, for the three curves below, the previous elldata package
reported incorrect results for ellgenerators():
69206d1, 284193m5, 284193m6
(the group generated by ellgenerators() wa a subgroup of finite index
of the Mordell-Weil group).

John Cremona has updated his Elliptic Curve Data to list smaller
generators, see <https://github.com/JohnCremona/ecdata/>
I have updated the PARI package elldata to match.

For detail, see
http://johncremona.github.io/ecdata/release_notes.md

This package contains elliptic curves defined over the rationals representing
all isogeny classes for all conductor at most 500000. Theses data are needed by
ellsearch, ellidentify and ellgenerators and require PARI/GP 2.2.11 and up.

The package can be downloaded from
<http://pari.math.u-bordeaux.fr/packages.html>

Thanks to John for providing this very useful database!

If diskspace is an issue, you can compress all the elldata/ell*
files using gzip, GP is able to read gziped files.

Cheers,
Bill.