Function: ellidentify
Section: elliptic_curves
C-Name: ellidentify
Prototype: G
Help: ellidentify(E): look up the elliptic curve E in the elldata database and
 return [[N, M, ...], C] where N is the name of the curve in J. E. Cremona
 database, M the minimal model and C the coordinates change (see
 ellchangecurve).
Doc:
 look up the elliptic curve $E$ (over $\Z$)
 in the \tet{elldata} database and return \kbd{[[N, M, G], C]}  where $N$
 is the name of the curve in the J.~E.~Cremona database, $M$ the minimal
 model, $G$ a $\Z$-basis of the free part of the \idx{Mordell-Weil group}
 of $E$ and $C$ the coordinates change (see \kbd{ellchangecurve}).
