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_self.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"net/http"
+)
+
+func ownerSelf(session string) (bool, owner) {
+	o, err := ownerGetBySession(session)
+	if err != nil {
+		return false, owner{}
+	}
+
+	return true, o
+}
+
+func ownerSelfHandler(w http.ResponseWriter, r *http.Request) {
+	type request struct {
+		Session *string `json:"session"`
+	}
+
+	var x request
+	if err := unmarshalBody(r, &x); err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	loggedIn, o := ownerSelf(*x.Session)
+
+	writeBody(w, response{"success": true, "loggedIn": loggedIn, "owner": o})
+}