Log Message:
Update to version 2.2.0.

Changes:
 
 * bigint input operator does no longer set failbit if it encounters EOF at
   the end of a number
 * fixed operator/(T a, bigrational const& b) for T != bigrational and a == 0.
 * fixed elliptic_curve<gf_element>::isomorphism_type(bigint&,
                                                      bigint&,
                                                      point< gf_element >&,
                                                      point< gf_element >&,
                                                      bool)
 * fixed HNF documentation.
 * fixed friend class declaration for param_desc.
 * Several bugfixes and cleanups in the MPQS and Lanczos code of
   single_factor<bigint>. (If the changes prove to be stable then
   rational_factorization will delegate all MPQS calls to
   single_factor<bigint> in further LiDIA releases.)
 * fixed build files for use with autoconf 2.59 / automake 1.9.6.
 * avoid fragile test of \pdfoutput in doc/{color.graphics}.cfg and use
   typearea.sty rather than geometry.sty due to a broken geometry.sty shipped
   with SuSE 10.0's teTeX 3.0.
 * fixed rational_factorization::compose() to prune really all factors with
   exponent 0.
 * many further small fixes...