Allow large bases
Rewrite n_is_prime and n_is_probabprime
Added copyright for Dana Jacobsen and copied large base code over to precomp
version of is_strong_probab_prime2.
Updates AUTHORS and manual.
Use precomputed inverse in large base mod operation in both versions of
n_is_strong_probabprime.
Added powers regression test to t-is_prime and t-is_probabprime.
Added regression test for composites that were being passed as prime, as
reported by Dana Jacobsen.
Updated code_conventions.txt regarding WORD/UWORD macros and flint_printf.
Update flint version number for 2.4.4 release.