Use autotools for csage
Try downloading on every status code (instead of 63 and 127 only)
Clean up weierstrass_p function
Fixes to code from #9505.
Fix changelog entry for ell_wp
Trac #15892: Followup to #9505

Because we are striving to be python3 compatible and #9505 adds a `<>`
when we have removed them all from the sage library in #13258. Also
indents are 4 spaces .

URL: http://trac.sagemath.org/15892
Reported by: tscrim
Ticket author(s): Travis Scrimshaw
Reviewer(s): Marc Mezzarobba
Trac #15855: Clean up weierstrass_p

Fix the precision bound for the quadratic algorithm and clean up the
code.

URL: http://trac.sagemath.org/15855
Reported by: jdemeyer
Ticket author(s): Jeroen Demeyer
Reviewer(s): Peter Bruin
Trac #15594: Use autotools for csage

Use autotools instead of scons to build `c_lib`. After this change,
polybori is the only part of Sage using scons.

URL: http://trac.sagemath.org/15594
Reported by: ohanar
Ticket author(s): R. Andrew Ohana, Jeroen Demeyer
Reviewer(s): R. Andrew Ohana, Jeroen Demeyer
Updated Sage version to 6.2.beta4