Added options for anti-alias & alpha layer coloring to config.def.h

Also removed now obsolete -p command line option; fixes issue #98

config.def.h

@@ -52,6 +52,19 @@ enum {
 /* default dimension of thumbnails (width == height): */
 enum { THUMB_SIZE = 60 };
 
+#endif
+#ifdef _RENDER_CONFIG
+
+/* if false, pixelate images at zoom level != 100%,
+ * toggled with 'a' key binding
+ */
+static const bool RENDER_ANTI_ALIAS = true;
+
+/* if true, use white background for alpha layer,
+ * toggled with 'A' key binding
+ */
+static const bool RENDER_WHITE_ALPHA = false;
+
 #endif
 #ifdef _MAPPINGS_CONFIG