Updating examples to Board changes, adding irq driver demo

Examples/blink/logic/blink.ucf

@@ -1,5 +1,5 @@
 NET clk   LOC = "P38";
-NET reset LOC = "P71";
+NET reset LOC = "P30";
 NET led   LOC = "P44";
 
 #ADDRESS BUS

Examples/blink/logic/blink.v

@@ -5,7 +5,7 @@ module blink(clk, reset, led);
 
   reg [24:0]  counter;
   always @(posedge clk) begin
-    if (reset)
+    if (~reset)
       counter <= {25{1'b0}};
     else
       counter <= counter + 1;