Elliptic Curves over the Rational Field

New features:

• Improvements have been made to the rank computation in the no two-torsion case.
• John Cremona's database of elliptic curves has been updated to conductor $10\,000$.

Bug fixes:

• A bug has been fixed in CremonaReference which would occasionally cause an incorrect reference to be returned.
• The computation of the torsion subgroup no longer crashes or returns incorrect results for curves with large coefficients.
• Various crashes in the rank computation have been fixed.