Proposed elldata database at the PARI workshop

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

Hello PARI dev,

For those of you who where at the PARI/GP workshop at Paris
(and for the other I encourage them to read the proceedings here:
<http://pari.math.u-bordeaux.fr/Events/IHP2004/>)
you might remember that John Cremona proposed to interface his elliptic
curves database with PARI/GP.

One of the idea was to change ellinit() to accept a curve name 
as a argument and extract the corresponding curve coefficients 
from the database.  For example we could do:
ellinit("11A1") instead of ellinit([0,-1,1,-10,-20])

Before I implement it, I would like to know what other features would
be useful in order to store the database in an efficient way.

Things I have considered so far:

- Retrieving all curves of a given conductor (elllist() ?)

- a forell(E=A,B,...) routine that would iterate through
all curves of conductors between A and B

Ideas ? Opinions ? Comments ?

Cheers,
Bill.