Log Message:
py-pyobjc: updated to 4.1

Version 4.1:
Protection agains buffer overflow and negative indexes in __getitem__ and \ 
__setitem__ for objc.varlist instances.

Fix incorrect metadata for +[NSEvent addLocalMonitorForEventsMatchingMask:handler:]

Fix incorrect and misleading error message in the exception that is raised when \ 
return a value from a block that should not return a value.

Issue 223: Fix hard crash when executing help(Cocoa)
Fetching the help for PyObjC framework wrappers isn’t very useful due to the \ 
sheer size of the output (4.5 million lines of output for help(Cocoa) at the \ 
moment), but shouldn’t cause a hard crash of the interpreter.

Issue 218: Explictly cause an ImportError when reloading `objc._objc`
Reloading the PyObjC core extension now raises an ImportError because this \ 
cannot work and used to raise a rather vague error.

Updated metadata for Xcode 9.2

Added missing `MAC_OS_X_VERSION_*` constants

Fix memory error in struct wrappers which resulted in a use-after-free error in \ 
the initializer for structs.

Add bindings for frameworks Security, SecurityFoundation and and SecurityInterface.
The bindings for the Security framework don’t expose a number of older APIs \ 
that were deprecated in macOS 10.7.

Add bindings to libdispatch.
These bindings require macOS 10.8 or later, libdispatch was available earlier \ 
but macOS 10.8 changed the API in such a way that wrapping became a lot easier.