add some features

- Export tex2D/sprites with PathID as a filename
- Dump selected assets from the context menu strip
- Drag&Drop support by Jayatubi
- Sort by PathID by Tahvohck

AssetStudioGUI/ExportOptions.cs

@@ -40,6 +40,7 @@ namespace AssetStudioGUI
             scaleFactor.Value = Properties.Settings.Default.scaleFactor;
             fbxVersion.SelectedIndex = Properties.Settings.Default.fbxVersion;
             fbxFormat.SelectedIndex = Properties.Settings.Default.fbxFormat;
+            pathIDAsImageName.Checked = Properties.Settings.Default.pathIDAsImageName;
         }
 
         private void OKbutton_Click(object sender, EventArgs e)
@@ -68,6 +69,7 @@ namespace AssetStudioGUI
             Properties.Settings.Default.scaleFactor = scaleFactor.Value;
             Properties.Settings.Default.fbxVersion = fbxVersion.SelectedIndex;
             Properties.Settings.Default.fbxFormat = fbxFormat.SelectedIndex;
+            Properties.Settings.Default.pathIDAsImageName = pathIDAsImageName.Checked;
             Properties.Settings.Default.Save();
             DialogResult = DialogResult.OK;
             Close();