Large test suite

---

examples/test-simple/tests/large_sum.txt

1, 1     =  2 
2, 2     =  4
2, 2, 2  =  6
3, 3     =  6
4, 4     =  8
5, 5     =  10
6, 6     =  12
7, 7     =  14
8, 8     =  16
19, 23   =  42
119, 123 =  242

# negative

-1, -1   = -2
-2, -1   = -3

# edge cases
0, 1    = 1
-0, 1    = 1
0, -1    = -1
-0, -1    = -1

1, 0    = 1
1, -0    = 1
2, 0    = 2
-1, 0   = -1
-1, -0   = -1

1, -1    = 0
2, -2    = 0
3, -3    = 0
4, -4    = 0
5, -5    = 0
6, -6    = 0
7, -7    = 0
8, -8    = 0
9, -9    = 0
10, -10    = 0
11, -11    = 0
12, -12    = 0
13, -13    = 0
14, -14    = 0
15, -15    = 0
16, -16    = 0
17, -17    = 0
18, -18    = 0
19, -19    = 0
20, -20    = 0
21, -21    = 0
22, -22    = 0
23, -23    = 0

$ cp tests/large_sum.txt tests/sum.txt

$ perl tests/t24.pl