HaroldMills/Vesper: v0.4.8

This release:

• Adds a Help dropdown that includes a link to draft Vesper documentation.
• Offers a reorganized navbar with clarified command names.
• Improves instructions on command forms.
• Improves clip calendar and clip album error handling.
• Adds a vesper_admin createarchive command that simplifies new archive creation.
• Allows control of which clips data are exported for in Export clip metadata to CSV file and Export clips to audio files commands.
• Adds support for BirdVoxDetect 0.2.x, including both adaptive threshold and fixed threshold versions of the detector.