merge plus fix the test spelling too

diff --cc lib/sqlalchemy/sql/compiler.py
Simple merge

diff --cc test/sql/test_compiler.py
index fe52402eca19d88486afbee08ee96c3db451368a,fe52402eca19d88486afbee08ee96c3db451368a..fa15c7aa2920933e6fa6cf41fa267dccfea1854b
--- 1/test/sql/test_compiler.py
--- 2/test/sql/test_compiler.py
+++ b/test/sql/test_compiler.py
@@@ -2211,14 -2211,14 +2211,14 @@@ class SelectTest(fixtures.TestBase, Ass
  
          assert_raises_message(
              exc.CompileError,
--            "Cannot compile Column object until it's 'name' is assigned.",
++            "Cannot compile Column object until its 'name' is assigned.",
              str, sel2
          )
  
          sel3 = select([my_str]).as_scalar()
          assert_raises_message(
              exc.CompileError,
--            "Cannot compile Column object until it's 'name' is assigned.",
++            "Cannot compile Column object until its 'name' is assigned.",
              str, sel3
          )