Done: P41

P41 (**) A list of Goldbach compositions.
Given a range of integers by its lower and upper limit, print a list of
all even numbers and their Goldbach composition.
scala> printGoldbachList(9 to 20)
10 = 3 + 7
12 = 5 + 7
14 = 3 + 11
16 = 3 + 13
18 = 5 + 13
20 = 3 + 17
In most cases, if an even number is written as the sum of two prime
numbers, one of them is very small. Very rarely, the primes are both
bigger than, say, 50. Try to find out how many such cases there are in
the range 2..3000.

Example (minimum value of 50 for the primes):

scala> printGoldbachListLimited(1 to 2000, 50)
992 = 73 + 919
1382 = 61 + 1321
1856 = 67 + 1789
1928 = 61 + 1867