Rust port of GNU Factor for 128-bit integers. Some changes have been made to my preference

1. Evaluation loop exits on the input of "q","quit" or "exit"

2. Hexadecimal input is supported with the --hex option

3. Factorisations are properly represented using exponentiation and multiplication symbols

4. Supports GNU factor style of formatting, with the provided --gnu flag

5. Supports formatting without repeating the factor, only outputting the factors.

Currently faster than the coreutils Rust port, and begins to outspeed GNU factor for n > 2^50.

Most semiprimes will be factored in less than 60 seconds (0.6s on average for 128-bit integers)

This performance is entirely due to the machine-factor library.

Running make install, installs it to /usr/bin and redefines factor to call this program instead.

For a drop-in replacement of GNU factor edit the .bash_aliases file to alias factor='/usr/bin/rfactor --gnu'

This code is licensed under GPLv3.