ckmame 2.1

• Add --report-changes to show changes between last and current run.
• Add --delete-unknown-pattern to remove unknown files matching a pattern.
• Switch to nihtest.

ckmame 2.0

• Support for configuration file and multiple sets.
• Overhaul command line options.
• Automatically update ROM DB.
• Speed up ROM sets with many files shared among many games.
• Improve parse error reporting, don't create mamedb for dats with errors, fix inconsistencies in dat.
• Improve detector support.

ckmame 1.1

• Read-only 7z support.
• Improve detector support.
• Bump mamedb version. All mame.db files need to be regenerated.
• Follow MAME in expecting disk images in subdirectories.
• Remove broken support for checking samples.
• Convert to C++17.