Differntiate allelic expansion with MAC codes

Depending upon whether the expanded alleles contains a `:` or not, the expansion should be treated differently.


```
	BJ	02/13
	BK	02/14
*	BM	13:05/13:06/13:07/13:09/14:05/14:08
	BN	01/04/08/13
	BP	01/04/05/07/08
```

`A*01:BJ` expands to `A*01:02/A*01:13`
while
`A*01:BM` expands to `A*13:05/A*13:06/A*13:07/A*13:09/A*14:05/14:08`
