* src/ColorDialog.cs: fix the contrast setting.

	* src/StockIcons.cs: add new icons.
	
	* src/PhotoView.cs: add desaturate button and sepia button.

	* src/ColorDialog.cs: add sepia and desaturate buttons.

	* src/Makefile.am: add new icons to resources.

	* src/IOChannel.cs: revert warning change.

	* src/MainWindow.cs: silence warning.

	* src/IOChannel.cs: get rid of some warnings.