Allow binary constants (e.g.: 0b01010)

- Add lexer and parser tests.
diff --git a/tests/test_c_parser.py b/tests/test_c_parser.py
old mode 100644
new mode 100755
index 5c7d723..61c3642
--- a/tests/test_c_parser.py
+++ b/tests/test_c_parser.py
@@ -1055,6 +1055,10 @@
         self.assertEqual(self.get_decl_init(d1_1),
             ['Constant', 'float', '0xEF.56p1'])
 
+        d1_2 = 'int bitmask = 0b1001010;'
+        self.assertEqual(self.get_decl_init(d1_2),
+            ['Constant', 'int', '0b1001010'])
+
         d2 = 'long ar[] = {7, 8, 9};'
         #~ self.parse(d2).show()
         self.assertEqual(self.get_decl(d2),