Fix binkp remote closing connection, add/delete session details, menu item this system, minor CSS fixes, move system form editing to individual files

app/Models/SystemZone.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class SystemZone extends Model
+{
+	protected $table = 'system_zone';
+
+	public function system()
+	{
+		return $this->belongsTo(System::class);
+	}
+
+	public function zone()
+	{
+		return $this->belongsTo(Zone::class);
+	}
+}