Update sqlalchemy stubs (#857)

I believe this covers both #647 and #719.

Moved sqlalchemy stubs from 2 to 2and3;
changed sqlalchemy/util/compat.pyi:37 to be of type typing.Text;
added incomplete stubs for sqlalchemy.orm.utils and slqalchemy.sql.elements.ColumnElement.

third_party/2and3/sqlalchemy/orm/__init__.pyi

@@ -1,4 +1,4 @@
-# Stubs for sqlalchemy.orm (Python 2)
+# Stubs for sqlalchemy.orm (Python 2 and 3)
 #
 # NOTE: This dynamically typed stub was automatically generated by stubgen.
 
@@ -6,7 +6,7 @@ from typing import Any
 # from . import mapper
 # from . import interfaces
 # from . import deprecated_interfaces
-# from . import util
+from . import util
 # from . import properties
 # from . import relationships
 # from . import descriptor_props
@@ -27,7 +27,7 @@ from ..util import langhelpers
 # MapperExtension = deprecated_interfaces.MapperExtension
 # SessionExtension = deprecated_interfaces.SessionExtension
 # AttributeExtension = deprecated_interfaces.AttributeExtension
-# aliased = util.aliased
+aliased = util.aliased
 # join = util.join
 # object_mapper = util.object_mapper
 # outerjoin = util.outerjoin

third_party/2and3/sqlalchemy/orm/session.pyi

@@ -1,4 +1,4 @@
-# Stubs for sqlalchemy.orm.session (Python 2)
+# Stubs for sqlalchemy.orm.session (Python 2 and 3)
 #
 # NOTE: This dynamically typed stub was automatically generated by stubgen.
 

third_party/2and3/sqlalchemy/orm/util.pyi

@@ -0,0 +1,12 @@
+# Stubs for sqlalchemy.orm.session (Python 2 and 3)
+from typing import Optional, Any, Text
+
+from ..sql.selectable import FromClause
+
+class AliasedClass(object):
+    def __init__(self, cls: Any, alias: Optional[FromClause] =None, name: Optional[Text] =None, flat: bool =False, adapt_on_names: bool =False,
+                 with_polymorphic_mappers: Any =(), with_polymorphic_discriminator: Any =None, base_alias: Any =None, use_mapper_path: bool =False) -> None: ...
+    def __getattr__(self, key): ...
+    def __repr__(self): ...
+
+def aliased(element: Any, alias: Optional[FromClause] =None, name: Optional[Text] =None, flat: bool =False, adapt_on_names: bool =False) -> AliasedClass: ...

third_party/2and3/sqlalchemy/sql/elements.pyi

@@ -1,3 +1,5 @@
+# Stubs for sqlalchemy.sql.elements (Python 2 and 3)
+from typing import Text, Any
 
 from .visitors import Visitable
 from .annotation import Annotated
@@ -7,7 +9,38 @@ from .. import util
 
 class ClauseElement(Visitable): ...
 
-class ColumnElement(ColumnOperators, ClauseElement): ...
+class ColumnElement(ColumnOperators, ClauseElement):
+    __visit_name__ = 'column'  # type: Text
+    primary_key = False  # type: Any
+    foreign_keys = []  # type: Any
+    _label = None
+    _key_label = key = None
+    _alt_names = ()
+    def self_group(self, against=None): ...
+    def _negate(self): ...
+    @util.memoized_property
+    def type(self): ...
+    @util.memoized_property
+    def comparator(self): ...
+    def __getattr__(self, key): ...
+    def operate(self, op, *other, **kwargs): ...
+    def reverse_operate(self, op, other, **kwargs): ...
+    def _bind_param(self, operator, obj): ...
+    @property
+    def expression(self): ...
+    @property
+    def _select_iterable(self): ...
+    @util.memoized_property
+    def base_columns(self): ...
+    @util.memoized_property
+    def proxy_set(self): ...
+    def shares_lineage(self, othercolumn): ...
+    def _compare_name_for_result(self, other): ...
+    def _make_proxy(self, selectable, name=None, name_is_truncatable=False, **kw): ...
+    def compare(self, other, use_proxies=False, equivalents=None, **kw): ...
+    def label(self, name): ...
+    @util.memoized_property
+    def anon_label(self): ...
 
 class BindParameter(ColumnElement): ...
 class BinaryExpression(ColumnElement): ...

third_party/2and3/sqlalchemy/sql/selectable.pyi

@@ -1,3 +1,5 @@
+from typing import Any
+
 from .base import Immutable, Executable, \
     ColumnCollection, ColumnSet, Generative
 from .elements import ClauseElement, TextClause, ClauseList, \
@@ -35,9 +37,9 @@ class FromClause(Selectable):
     @property
     def columns(self): ...
     @property
-    def primary_key(self): ...
+    def primary_key(self) -> Any: ...
     @property
-    def foreign_keys(self): ...
+    def foreign_keys(self) -> Any: ...
     def _init_collections(self): ...
     @property
     def _cols_populated(self): ...

third_party/2and3/sqlalchemy/util/compat.pyi

@@ -1,6 +1,6 @@
 # Stubs for sqlalchemy.util.compat (Python 2)
 
-from typing import Any
+from typing import Any, Text
 from collections import namedtuple
 
 import threading
@@ -34,7 +34,7 @@ def inspect_getargspec(func): ...
 
 string_types = ...  # type: Any
 binary_type = ...  # type: Any
-text_type = unicode
+text_type = Text
 int_types = ...  # type: Any
 
 def callable(fn): ...