Pipette and "On Preview Widgets" branch. See issue 227

The pipette part is already working quite nice but need to be finished. The widgets part needs more work...

rtengine/klt/base.h

@@ -0,0 +1,27 @@
+/*********************************************************************
+ * base.h
+ *********************************************************************/
+
+#ifndef _BASE_H_
+#define _BASE_H_
+
+#ifndef uchar
+#define uchar unsigned char
+#endif
+
+#ifndef schar
+#define schar signed char
+#endif
+
+#ifndef uint
+#define uint unsigned int
+#endif
+
+#ifndef ushort
+#define ushort unsigned short
+#endif
+
+#ifndef ulong
+#define ulong unsigned long
+#endif
+#endif