ref: 993baaf1029e1379aea6a6045fff97015f042cce
parent: 97888140d15254059c5520fba21ba2bfc6d0bf86
author: Fabian Greffrath <fabian@greffrath.com>
date: Thu Sep 3 05:25:22 EDT 2015
Pass a parameter to I_BeginRead() to force it to backup the background Also, draw disk icon by means of V_DrawPatch(), thanks @jmtd.