Hello all,

Here are ten patches to improve numerics.  Among other things, this
eliminates the known obstacles to linking with mini-gmp
<http://bugs.gnu.org/10519>, fixes several problems with our number
printer <http://bugs.gnu.org/13757>, adds 'round-ash', and speeds up
handling of exact rationals.

Still to be done: add more tests to ensure full coverage of all code
paths.  It's possible that there are some bugs lurking.  However, I
wanted to post it now to allow review and possible work on mini-gmp
integration.

Comments and suggestions welcome.

     Mark