Basically, if a rom is a duplicate, it can be a duplicate within a system or source or across system or source, and by hash alone or by all data matching. The four combinations make an enum now and the diff function is the only one that uses them right now. If we're in dedup mode, we want to check hashes only in diff. Otherwise, we want to check against ones that match all information. This needs field testing.
This change brings about a few changes:
1) A new LogLevel called "User" that is used for non-verbose, non-error output
2) Only User and Error are output to console now, not all of them
3) All programs have log to file enabled by default and all flags for enabling logging have been removed
4) Some former Verbose statements have been converted over to User because of the shift in usage.
