add album-pic and lyric download
add mutagen module for image in mp3 file. auto merge lyrics,album art,album name,artist name,music title into the mp3 file
remove debug message
Merge branch 'fooling-master'

TODO: Fix issues listed in comment section of issue #1
[Fix]: Merging aftermath: Fix Unicode Error.
[Mod]: Merging aftermath: Make mutagen optdep.
[Ref]: Merging aftermath: Make tagging seperate.
[Ref]: Remove useless import.
[Fix]: Lyrics encoding. (with small refactoring)
[Ref]: Explicit module naming. (comments added)
[Fix]: Possibly fix the encoding problem.
[Doc]: add --no-tag option.
[Add]: License.