Fix "sys.excepthook is missing" warnings

Add more imp.* functions, set correct module.__file__, import * with non module globals

Get `cpython/test_property.py` to pass

by adding sys.excepthook.

Add pyxl hello world integration test

Add support for weakref.proxy

add imp.is_builtin, imp.is_frozen, imp.new_module, support object.__hash__(arg), don't always set module.__file__

Add support for specifying the encoding inside source files.

Support for inspect.isgenerator, round(int), property.__doc__

Sqlalchemy tests

Apparently the 'assert' statement works by looking up the "AssertionError"
name in the global scope, and then raising an exception of that type.

pytest uses this to override assertion behavior.

By replacing the entry in sys.modules.  pytest does this.

This was preventing subclasses of module from overriding __init__.
Yes, that really happens.

sqlalchemy uses pytest to run its test suite, which unfortunately
has been hard to get working.

I had to change 'new_weakref' to use 'tp_alloc' instead of 'PyObject_GC_New'
in order to create a weak ref because 'PyObject_GC_New' allocated memory
is scanned conservatively.
'tp_alloc' points to 'PystonType_GenericAlloc' and is of PYTHON type.

Ignore generated tmp folders.

visit im_class in gc handler

-m support

In particular this helps with our support for throwing
old-style classes as exceptions.

made the checks in CheckExact

zip() takes varargs. django passes 3 containers to it.

Fix speculations at module scope

Conflicts:
	src/runtime/objmodel.cpp

Closes #466

Add im_class field to BoxedInstanceMethod, implement instancemethodRepr

Add support for string interning

Handle map(None,...), exec with module.__dict__ as globals