api: Add go files

I know this is a huge commit, but I can't be bothered to check
this in part by part.

api/domain_delete.go

@@ -0,0 +1,52 @@
+package main
+
+import ()
+
+func domainDelete(domain string) error {
+	if domain == "" {
+		return errorMissingField
+	}
+
+	statement := `
+		DELETE FROM
+		domains
+		WHERE domain = $1;
+	`
+	_, err := db.Exec(statement, domain)
+	if err != nil {
+		return errorNoSuchDomain
+	}
+
+	statement = `
+		DELETE FROM votes
+		USING comments
+		WHERE comments.commentHex = votes.commentHex AND comments.domain = $1;
+	`
+	_, err = db.Exec(statement, domain)
+	if err != nil {
+		logger.Errorf("cannot delete votes: %v", err)
+		return errorInternal
+	}
+
+	statement = `
+		DELETE FROM views
+		WHERE views.domain = $1;
+	`
+	_, err = db.Exec(statement, domain)
+	if err != nil {
+		logger.Errorf("cannot delete views: %v", err)
+		return errorInternal
+	}
+
+	statement = `
+		DELETE FROM comments
+		WHERE comments.domain = $1;
+	`
+	_, err = db.Exec(statement, domain)
+	if err != nil {
+		logger.Errorf(statement, domain)
+		return errorInternal
+	}
+
+	return nil
+}