vs4win/Chapter04/PrimeFactorsLib/Primes.cs ugh

[DickBaker]

1. [YAGNI] given spec of "largest number entered will be 1,000" you can reduce the size of PrimeNumbers array to exclude the 997 - 503 entries
2. [Perf] divisor cannot exceed number subject so loop can be short-circuited (e.g. with LINQ Where)
3. [Perf] if (number == 1) is satisfied, code should immediately return the result instead of labouring over [many] subsequent iterations

I will submit my contender FYI as PR, but imho current reference solution sucks

• enjoy red-penning mine!