Added a queue implementation

Added a queue to the stdlib and a test case for it.

tests/test_queue.expected_results

@@ -0,0 +1,67 @@
+adding to q
+pushing...
+0
+pushing...
+1
+pushing...
+2
+pushing...
+3
+pushing...
+4
+pushing...
+5
+pushing...
+6
+pushing...
+7
+pushing...
+8
+pushing...
+9
+adding to q2
+pushing...
+9
+pushing...
+8
+pushing...
+7
+pushing...
+6
+pushing...
+5
+pushing...
+4
+pushing...
+3
+pushing...
+2
+pushing...
+1
+pushing...
+0
+pop test...
+0
+q is about to pop
+q popped
+q2 is about to pop
+9
+8
+7
+6
+5
+4
+3
+2
+1
+0
+1
+2
+3
+4
+5
+6
+7
+8
+9
+done