wrtag v0.15.0

Features

• metadata: print keys in order they came (7abac5d)
• musicdesc: new addon for key and bpm detection (53b79bd), closes #110 #109
• wrtagweb: add pprof handlers (82f87b3)
• wrtag: write COMPOSER tag (1dad865)
• wrtag: write ISRC tag (5004569)

Bug Fixes

• wrtag: handle case where src dirs have string prefix of path-format root (2162391), closes #135