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_get.go

@@ -0,0 +1,29 @@
+package main
+
+import ()
+
+func domainGet(dmn string) (domain, error) {
+	if dmn == "" {
+		return domain{}, errorMissingField
+	}
+
+	statement := `
+    SELECT domain, ownerHex, name, creationDate, state, importedComments, autoSpamFilter, requireModeration, requireIdentification
+		FROM domains
+		WHERE domain = $1;
+	`
+	row := db.QueryRow(statement, dmn)
+
+	var err error
+	d := domain{}
+	if err = row.Scan(&d.Domain, &d.OwnerHex, &d.Name, &d.CreationDate, &d.State, &d.ImportedComments, &d.AutoSpamFilter, &d.RequireModeration, &d.RequireIdentification); err != nil {
+		return d, errorNoSuchDomain
+	}
+
+	d.Moderators, err = domainModeratorList(d.Domain)
+	if err != nil {
+		return domain{}, err
+	}
+
+	return d, nil
+}