Log exception and return null on xpm loading failure. Add copyright

src/dlangui/graphics/images.d

@@ -64,9 +64,15 @@ ColorDrawBuf loadImage(immutable ubyte[] data, string filename) {
     import std.algorithm : endsWith;
     if (filename.endsWith(".xpm")) {
         import dlangui.graphics.xpm.reader;
-        
+        try {
             return parseXPM(data);
         }
+        catch(Exception e) {
+            Log.e("Failed to load image from file ", filename);
+            Log.e(to!string(e));
+            return null;
+        }
+    }
     
     version (USE_DEIMAGE) {
         try {

src/dlangui/graphics/xpm/reader.d

@@ -1,5 +1,14 @@
 module dlangui.graphics.xpm.reader;
 
+/**
+ * Reading .xpm files.
+ * 
+ * Copyright: Roman Chistokhodov, 2015
+ * License:   Boost License 1.0
+ * Authors:   Roman Chistokhodov, freeslave93@gmail.com
+ * 
+ */
+
 import dlangui.graphics.xpm.colors;
 
 import dlangui.graphics.colors;