Unit test failures in version 3.2.0

[Rafael Laboissière <rafael@debian.org>]

I did some work on version 3.2.0-1 of the octave-interval package, fixing 
an upstream bug that was preventing the package to build.[*]

Compilation goes fine, but 55 unit tests fail with the error message 
"mpfr_to_string_d: Illegal format".

Could someone (Oliver?) try to fix the problems?

Rafael

[*] https://savannah.gnu.org/bugs/index.php?54234