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/owner_get.go

@@ -0,0 +1,48 @@
+package main
+
+import ()
+
+func ownerGetByEmail(email string) (owner, error) {
+	if email == "" {
+		return owner{}, errorMissingField
+	}
+
+	statement := `
+    SELECT ownerHex, email, name, confirmedEmail, joinDate
+    FROM owners
+    WHERE email=$1;
+  `
+	row := db.QueryRow(statement, email)
+
+	var o owner
+	if err := row.Scan(&o.OwnerHex, &o.Email, &o.Name, &o.ConfirmedEmail, &o.JoinDate); err != nil {
+		// TODO: Make sure this is actually no such email.
+		return owner{}, errorNoSuchEmail
+	}
+
+	return o, nil
+}
+
+func ownerGetBySession(session string) (owner, error) {
+	if session == "" {
+		return owner{}, errorMissingField
+	}
+
+	statement := `
+    SELECT ownerHex, email, name, confirmedEmail, joinDate
+		FROM owners
+		WHERE email IN (
+			SELECT email FROM ownerSessions
+			WHERE session=$1
+		);
+	`
+	row := db.QueryRow(statement, session)
+
+	var o owner
+	if err := row.Scan(&o.OwnerHex, &o.Email, &o.Name, &o.ConfirmedEmail, &o.JoinDate); err != nil {
+		logger.Errorf("cannot scan owner: %v\n", err)
+		return owner{}, errorInternal
+	}
+
+	return o, nil
+}