On the initial commit of this feature, IPs were just matched with a
very simple regex that prioritised simplicity/readability over
accuracy.
This commit adds a postprocessor for ip matches that makes use of
Python's `ipaddress` in the standard library to validate all the IP
matches.
This way we don't need huge and complex regex patterns to match _and_
validate the IPs, and we can just use `ipaddress` to abstract us from
implementing all the validation logic into the regex pattern.
Without this fix the file with the list of notifications looks like this:
```
0.19.0,1601899026.4373078,<built-in method count of Notification object at 0x7f8c582193b0>
```
which ends up notifying about a new version all the time.
There was a warning when the CI executed the "macOS Brew" job:
```
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
```
To fix this, use pip3 instead of pip.
The new User Notifications Framework is only available on macOS 10.14 and above, while the old NSUserNotification API is deprecated in macOS 11 (Big Sur) and will probably be removed in the future.
This commit compiles a simple test program to see if the Framework is available and then uses either the new or the old API.
When piping the output of `setup.py` to another program, that program cannot usually deal with escape sequences well. To fix this, output the compilation progress on new lines instead of overwriting the current line.
Disabling Link Time Optimization is useful for Nix on Darwin because LTO is broken there and has been for a long time, see https://github.com/NixOS/nixpkgs/pull/19312.
This is currently worked around in the Nix package with a patch that removes the lines that add -flto to the compiler flags.
This used to be implemented before 4e3c6e52aad41b9deb98d052c806f4a84846b782, when the now deprecated notifications framework was still being used.
Implement it again for feature parity.
