* Syntax cleanup
* More minor cleanup, use Linq
* Fix broken features by using correct values
* Feature flags the same
* Features are modular
* No AlphaFS, more .NET versions
* Fix appveyor
* Put back identifiers, for some reason
* String interpolation, modernization
* Better use of GetField
* XmlTextWriter to remove possible issues
* Fix header for OpenMSX
This DOES group some kinds of DAT due to their inherently similar nature. TSV and CSV are under the same "SeparatedValue" umbrella, and all of the SFV, MD5, SHA1, etc are under Hashfile because they're nearly identical. This is just the first stage change, making everything static and making them reference the DatFile separately.