ui: color schemes

Put all colors into single xml file. Accessing colors is handled via the singleton class ColorScheme. The default scheme
"bright.xml" holds the original colors. The scheme "dark.xml" is a start, but still a poor alternative. Color schemes
can be switched via the View menu.

src/lib/utility/messaging/type/MessageSwitchColorScheme.h

@@ -0,0 +1,23 @@
+#ifndef MESSAGE_SWITCH_COLOR_SCHEME_H
+#define MESSAGE_SWITCH_COLOR_SCHEME_H
+
+#include "utility/messaging/Message.h"
+
+class MessageSwitchColorScheme
+	: public Message<MessageSwitchColorScheme>
+{
+public:
+	MessageSwitchColorScheme(const std::string& filePath)
+		: colorSchemeFilePath(filePath)
+	{
+	}
+
+	static const std::string getStaticType()
+	{
+		return "MessageSwitchColorScheme";
+	}
+
+	const std::string colorSchemeFilePath;
+};
+
+#endif // MESSAGE_SWITCH_COLOR_SCHEME_H