0.11

• Rename all encodings. E.g. ENISO → EncodingISO
• Add NewEmptyTag constructor. Thanks to @corneldamian! #22
• Return compatibility with old versions of Go. Thanks to @mro for report! #25
• Fix race condition in util.FormSize d911cfa
• Add tag.Reset function 2ccdfea
• Performance compared to v0.10:

name                   old time/op    new time/op    delta
ParseAllFrames-4          201µs ± 1%     212µs ± 2%   +5.44%  (p=0.001 n=6+7)
ParseArtistAndTitle-4    76.9µs ± 4%    56.9µs ± 2%  -25.97%  (p=0.001 n=7+7)
ParseAndWrite-4          10.1ms ± 1%    10.2ms ± 4%   +0.68%  (p=0.945 n=6+7)

name                   old alloc/op   new alloc/op   delta
ParseAllFrames-4          526kB ± 0%     525kB ± 0%   -0.32%  (p=0.001 n=7+7)
ParseArtistAndTitle-4      683B ± 0%      716B ± 0%   +4.75%  (p=0.001 n=7+7)
ParseAndWrite-4           299kB ± 0%     267kB ± 0%  -10.65%  (p=0.001 n=7+7)

name                   old allocs/op  new allocs/op  delta
ParseAllFrames-4           95.0 ± 0%      95.0 ± 0%     ~     (all equal)
ParseArtistAndTitle-4      24.0 ± 0%      25.0 ± 0%   +4.17%  (p=0.001 n=7+7)
ParseAndWrite-4             101 ± 1%       102 ± 1%   +0.99%  (p=0.012 n=7+7)