Log Message:
update to 2.3.0
changes:
-New functions mpfr_j0, mpfr_j1, mpfr_jn, mpfr_y0, mpfr_y1, mpfr_yn,
 mpfr_lgamma, mpfr_remainder, mpfr_remquo, mpfr_fms, mpfr_signbit,
 mpfr_setsign, mpfr_copysign, mpfr_get_patches
-Functions mpfr_sin, mpfr_cos and mpfr_sin_cos improved
-More detailed MPFR manual
-Improved tests (make check)
-Bug fixes