Move scanners in its own directory. Dir base-tests -> base_tests so we

can import from that.

test/base_tests/python2.7/test_global.py

@@ -0,0 +1,16 @@
+i = 1; j = 7
+def a():
+    def b():
+        def c():
+            k = 34
+            global i
+            i = i+k
+        l = 42
+        c()
+        global j
+        j = j+l
+    b()
+    print i, j # should print 35, 49
+
+a()
+print i, j