Added checksum class and first algo for DE
rspec config: backtrace_clean_patterns
Checksum: Added BE support
Checksum: Added DK support
Checksum: Added FI support
Checksum: Added GR support
Checksum: Moved logic from lambdas to classes
Checksum: Added IE support (new vat format)
Checksum: Added IE support (old vat format)
Checksum: Added IT support
Checksum: Added LU support
Checksum: Added NL support
Checksum: Added AT support
Moved country specific checksums into separat files
Minor spec naming fix
Checksum: Added PL support
Minor simplification for Checksum::FI
Checksum: Added PT support
Ficxed Checksum::PT spec
Checksum: Added SE support