Add Python 3 modules, and more Python 2 modules.

Also, sort names alphabetically and add module docstrings.

python2/cStringIO.py

@@ -0,0 +1,41 @@
+"""Stub file for the 'cStringIO' module."""
+# This is an autogenerated file. It serves as a starting point
+# for a more percise manual annotation of this module.
+# Feel free to edit the source below, but remove this header when you do.
+
+InputType = Undefined(StringI)
+OutputType = Undefined(StringO)
+cStringIO_CAPI = Undefined(object)
+
+def StringIO(*args, **kwargs) -> object: pass
+
+
+class StringI(object):
+    def close() -> NoneType: pass
+    def flush() -> NoneType: pass
+    def getvalue(*args, **kwargs) -> str: pass
+    def isatty() -> bool: pass
+    def read(*args, **kwargs) -> str: pass
+    def readline(*args, **kwargs) -> str: pass
+    def readlines(*args, **kwargs) -> List[str]: pass
+    def reset() -> NoneType: pass
+    def seek(a: int, *args, **kwargs) -> NoneType: pass
+    def tell() -> int: pass
+    def truncate(*args, **kwargs) -> NoneType:
+        raise IOError()
+
+class StringO(object):
+    def close() -> NoneType: pass
+    def flush() -> NoneType: pass
+    def getvalue(*args, **kwargs) -> str: pass
+    def isatty() -> bool: pass
+    def read(*args, **kwargs) -> str: pass
+    def readline(*args, **kwargs) -> str: pass
+    def readlines(*args, **kwargs) -> List[str]: pass
+    def reset() -> NoneType: pass
+    def seek(a: int, *args, **kwargs) -> NoneType: pass
+    def tell() -> int: pass
+    def truncate(*args, **kwargs) -> NoneType:
+        raise IOError()
+    def write(a) -> NoneType: pass
+    def writelines(*args, **kwargs) -> NoneType: pass