added library qappgen-validators
started to work on validator infrastructure
added DatabaseCastValidator
simplification: template method createValidator<T> created
cleanup
added DatabaseCastValidator
added DatabaseDataTypeVAlidator
added DatabaseDomainValidator
added DatabaseEncodingConversionValidator
added DatabaseEncodingConversionValidator
added DatabaseFunctionValidator
added DatabaseLanguageValidator
added DatabaseOperatorClassValidator
added DatabaseOperatorValidator
added DatabaseOperationFamilyValidator
added DatabaseRoleValidator
added DatabaseSchemaValidator
added DatabaseSequenceValidator
added DatabaseTableValidator
added DatabaseTablespaceValidator