First implementation based on int
Added file for GMP backend
Initial support for GMP
Install ctypes with Python 2.4
Fix problem with 64-bit machines and ctypes (long)
Workaround for pip bug (wrong permission after unpacking)
Stricter definitions for parameters to C calls
Added exponentiation to Natural
Unit test will cover both Natural implementations
Added more methods to Natural

Methods and operators added:
* random()
* and
* comparison
* bool
* in-place right shift
* size_in_bits()
* str
* is_even()
* is_odd()
Miller-Rabin test
Add is_perfect_square method to Natural
Simplify GMP code with _as_parameter_
Added more methods to Natural.

Methods and operators added are:
* jacobi_symbol()
* multiplication
* simple exponentiation
* right shift
Change Math.Numbers.Natural into Integer
Add Lucas primality test
Added script to plot Miller-Rabin error probability
Add or operator to Integer
Added generate_probable_prime function
Added plot for bit sizes 160..512