Implement full improved Baillie-PSW test

[fjarri]

This is a follow-up to #3. The same paper proposes an improved BPSW test (Section 6). The test consists of:

• MR test with base 2
• Lucas base A* (the base selection can uncover the candidate to be composite; see the paper for details)
• Strong Lucas check
• Lucas-V check
• Check that Q^((n+1)/2) == Q * Jacobi(Q, n) (using the powers of Q already calculated during the Lucas test)

This can be made a separate preset.

Problems:

• There don't seem to be any inputs to lucas_test() that would allow one to reach the last step, so not sure how it should be tested.
• Complicates the check structure in lucas_test() since if "New-BPSW" is active, strong Lucas check cannot terminate prematurely anymore. But maybe it won't be too bad.