gappa v0.8.0

Notable Changes

• Add filter command
• Add merge command
• Add lwr-distribution command and helper script
• Refactor lwr command into lwr-histogram and lwr-list
• Add --distant-label option for assign command
• Rename module random to simulate
• Refine a lot of documentation and option descriptions
• Refine automatic thread number guessing to use OpenMP
• Fix nan issue in KR distance computation