CALL and RET instructions.

Changed PSHP and POPP into CALL and RET, streamlining their use for subroutine calls.
Updated Assembler and Emulator.
New demonstration programs.

Source/Assembler/Assembler.c

@@ -71,11 +71,14 @@ void assemblerCleanup(intermediateElement *intermediateArray, int arraySize, cha
     }
     // Free the intermediateArray itself.
     free(intermediateArray);
+
     // Free the list of included files.
     freeIncludeList();
+
     // Free the list of labels.
     freeLabelList();
-    // Free the output file name.
+
+    // Free the output file name
     free(outputFileName);
 }