added license, moved cell libs into repo

added buffer (not tested),

test/unit_tests/fifo3_8bit/test.prsim

@@ -0,0 +1,40 @@
+
+set-channel-neutral "t.A" 8
+set t.Y.a 0
+
+cycle
+system "echo 'reset completed'"
+status X
+set Reset 0
+mode run
+cycle
+
+assert t.A.a 0
+assert-channel-neutral "t.Y" 8
+
+set-channel-valid "t.A" 8 2
+
+system "echo 'sending first set A'"
+cycle
+assert t.A.a 1
+set-channel-neutral "t.A" 8
+cycle
+assert t.A.a 0
+
+system "echo 'checking first set'"
+assert-channel-valid "t.Y" 8 2
+set t.Y.a 1
+
+cycle
+assert-channel-neutral "t.Y" 8
+set t.Y.a 0
+
+system "echo 'sending second set'"
+set-channel-valid "t.A" 8 95
+cycle
+assert t.A.a 1
+set-channel-neutral "t.A" 8
+cycle
+system "echo 'checking second set'"
+assert t.A.a 0
+assert-channel-valid "t.Y" 8 95