socket: Add socket.error

Older CPython versions raised socker.error (or classes derived from it)
as exceptions on errors. Various software still uses it to be compatible
with older Python versions. As it's one-line fix, allow MicroPython to
run such code too.

try:
  socket...
except socker.error as e:
  ...

socket/metadata.txt

@@ -1,4 +1,4 @@
 srctype = micropython-lib
 type = module
-version = 0.3.2
+version = 0.3.3
 author = Paul Sokolovsky

socket/setup.py

@@ -6,7 +6,7 @@ from setuptools import setup
 
 
 setup(name='micropython-socket',
-      version='0.3.2',
+      version='0.3.3',
       description='socket module for MicroPython',
       long_description="This is a module reimplemented specifically for MicroPython standard library,\nwith efficient and lean design in mind. Note that this module is likely work\nin progress and likely supports just a subset of CPython's corresponding\nmodule. Please help with the development if you are interested in this\nmodule.",
       url='https://github.com/micropython/micropython/issues/405',

socket/socket.py

@@ -7,6 +7,8 @@ IPPROTO_IP = 0
 IP_ADD_MEMBERSHIP = 35
 IP_DROP_MEMBERSHIP = 36
 
+error = OSError
+
 def _resolve_addr(addr):
     if isinstance(addr, (bytes, bytearray)):
         return addr