Output the size of the metadata tags, and add support for detecting APE tags

Discovered the existence of APE tags today while inspecting a few MP3s.  I'm not sure how common they are, but it was helpful to know they were there for my purposes (especially since some MP3 inspectors erroneously identified them as id3v1).  

http://wiki.hydrogenaudio.org/index.php?title=APEv2_specification
http://audacity.googlecode.com/svn/audacity-src/trunk/lib-src/taglib/taglib/ape/ape-tag-format.txt

Additionally, I needed to know the size of the id3 tags, mostly to find files where large image files where embedded as cover art.  Those values were already being computed so I added the information to the program's output so I  could access it.

Thought I'd contribute back just in case someone else finds this useful!