* mpz_fits_* and 31 vs. 32 integer variables
* all apropriate module and class methods if there are any to add
* fix all sign issues
* floats with precision control
* random numbers
* to_s vs. inspect ?
* to_s_hex()
* check if mpz_addmul_ui would optimize some statements
* some system that allow using denref and numref as normal ruby objects
* should we allocate global temporary variables like Perl GMP do ?
* takeover code that replaces all Bignums with GMP::Z
* better bignum parser
* zero-copy method for strings generation
* what should be ancestors of GMP::* classes ?
* division and modulo
* check if it installs, add deb/rpm/whatever
* put it on some website
* put rb_raise into nice macros
* benchmarks against Python GMP and Perl GMP
* dup methods
* integrate F into system
* should Z.[] bits be 0/1 or true/false, 0 is true, what might badly surprise users
* seriously investigate Ruby Makefile-making system
* any2small_integer()
* autoindent code
* check asm output, especially local memory efficiency
* it might be better to use `register' for some local variables
* powm with negative exponents
* check if different sorting of operatations gives better cache usage,
* GMP::* op RubyFloat and RubyFloat op GMP::*
* sort checks
* check all new GMP4 operations