Very big and ugly memory leaks

[Amiaux Benoit]

Sorry, I must disagree. 'tag' points to whatever tag is present. If it's 
only a id3v1 tag, 'ID3v1Tag' and 'tag' will point to the same object. 
Same for Apetag. If both id3v1 and ape tags are present in the file, 
current code merge them, and again, 'tag' is assigned to the right 
object. I didn't check too much the combineTag code though, this part 
may still leak if the two remaining tags aren't cleaned properly.
When only one tag is present, deleting anything more than 'tag' will 
lead to segmentation faults.