Permit UDB config to set the per-texture offsets.

extras/conf/udb/Includes/SRB222_common.cfg

@@ -202,6 +202,9 @@ mapformat_udmf
 	defaultsavecompiler = "zdbsp_udmf_normal";
 	defaulttestcompiler = "zdbsp_udmf_fast";
 
+	// Enables support for individual offsets of upper/middle/lower sidedef textures
+	localsidedeftextureoffsets = true;
+
 	// Determines the textmap namespace
 	engine = "srb2";