Stack handling improved - no more StackEmptyException

And/Or handling improved
Preprocessor instructions introduced - §§pop,§§push...

libsrc/ffdec_lib/src/com/jpexs/decompiler/graph/SimpleValue.java

@@ -0,0 +1,10 @@
+package com.jpexs.decompiler.graph;
+
+/**
+ *
+ * @author JPEXS
+ */
+public interface SimpleValue {
+
+    public boolean isSimpleValue();
+}