fixed release code
added 5 attributes

#encoder, #group, #composer, #lyrics, #compilation?
added 4 attributes

#subtitle, #bpm, #lyricist, #copyright
renamed #encoder to #encoded_by; added #encoder_settings
#comments now returns a list, #comment returns the first obj in that list
switched frame id lookup for #encoded_by and #encoder_settings
added scalable attribute system
removed attrib_args which are set to their defaults
added support for #comments and #album_art in new system
pass self instead of just taglib to attributes
added support for Proc and #user_info in new system
added #date in new attrib system
first commit for MP4 attribute system
fix for @default dup error
properly clone default attr
added all mp4 attributes to new system
bump to 0.3.0
Merge branch 'develop'