Bug in Prime Tests, gcd != 1

[furun]

There is a bug in some prime tests.

This lines are wrong, it fails to detect if gcdTest.dataLength > 1

if (gcdTest.dataLength == 1 && gcdTest.data[0] != 1)

it should be

if (gcdTest.dataLength > 1 || gcdTest.dataLength == 1 && gcdTest.data[0] != 1)

(I replaced all this check with IsNegative, IsOne, IsOdd, etc.
Sad that this code is not supposed anymore, it is the best c# code I know)

[bazzilic]

Hi, .NET now has its own, built-in BigInteger class, which is better than what was implemented here. It lacks some functions, which can be found in our other project (https://github.com/aprismatic/bigintegerext) that extends the built-in class.