Further optimize the implementation of Hermite Normal Form in Sage

PEOPLE: Clement Pernet, William Stein

SUMMARY: Do the following:

  1. Rewrite add row to (a) use a block method, and (b) use fast non-recursive code (it is silly right now).
  2. Implement (or wrap?) Clement's "twice as fast" double det. ---> done(cpernet 03/01/08), still need some tune-up.

  3. Improve LinBox rational solver: efficiency with small size entries, endianness issue making it brake on solaris;

    • Wrap it in sage
  4. Validate linbox-1.1.5rc1.spkg and givaro-3.2.10.spkg for sage-2.10.3