Replaced use of custom 'baseUrl' helper with 'url'

Also changed up how base URL setting was being done
by manipulating incoming request URLs instead of
altering then on generation.

app/Http/Request.php

@@ -0,0 +1,26 @@
+<?php namespace BookStack\Http;
+
+use Illuminate\Http\Request as LaravelRequest;
+
+class Request extends LaravelRequest
+{
+
+    /**
+     * Override the default request methods to get the scheme and host
+     * to set the custom APP_URL, if set.
+     * @return \Illuminate\Config\Repository|mixed|string
+     */
+    public function getSchemeAndHttpHost()
+    {
+        $base = config('app.url', null);
+
+        if ($base) {
+            $base = trim($base, '/');
+        } else {
+            $base = $this->getScheme().'://'.$this->getHttpHost();
+        }
+
+        return $base;
+    }
+
+}