add diskpacked storage system

Change-Id: Ieb16459c06d596ad49bbe78b6e058955fcd6f649
Merge "add diskpacked storage system"
Basic code to index id3 (and other audio) tags.

Does a few things:

1) Adds gotaglib to third_party. If you'd like to review that, feel
free, though there's a bit of organization I'd like to do first.

2) Adds an "audioTag" key type.

3) Indexes wholerefs by various audio tags. Doesn't yet add a map from
wholeref to tags, but I can add that next.

Change-Id: I8e2a5bc27260086bad3351ac57973d1ac23cff44
Merge "Basic code to index id3 (and other audio) tags."
diskpacked: cleanups

Change-Id: I91566b120698b618ad4f83468a0cd4ea2c0ae765
search: actually use result of SearchPermanodesWithAttr and don't leak a goroutine

Change-Id: Ia1ff8acc1d396901c6b589dbe9a972e3dd4df05f
Merge branch 'master' of https://camlistore.googlesource.com/camlistore