Screen-brightness-control

* Add new `Display` dataclass to replace old `Monitor` class
* `Monitor` is now deprecated for removal in v0.23.0
* Add ability to disable `--async` flag in `linux.DDCUtil`
* Add new type aliases with better descriptions of what they mean (see 5fa542f, 20c3dea)
* Fix not all monitor handles being properly cleaned up in `windows.VCP`
* Refactor `fade_brightness`
* Remove redundant type info in docstrings (see 0431b53)
* Remove redundant docstrings (see 20c3dea)
* Deprecate `Monitor.__getitem__` behaviour for removal in v0.22.0
* Deprecate using a display's model to identify it. Use the name instead. Will be removed in v0.22.0
* Deprecate unused top-level imports for removal in v0.22.0:
* `MONITOR_MANUFACTURER_CODES`
* `debug_info`

* Merge 28 Added increment change for --set in command line argument from ujjukumar
* Add ability to look up method name via `get_methods`
* Rework exceptions (see d5f1bdd)
* New exceptions added. Should all be backwards compatible
* Refactor:
* `windows.get_display_info` - removed massive generic try/except blocks
* `helpers.EDID.parse` - more helpful exceptions
* `filter_monitors` - better readability
* More consistent use of "display", "screen" and "monitor" terminology (see 46bfac2)

* Merge 27 Added Gigabyte manufacturer code, and added gitignore file from ujjukumar
* Enable configuration of max retries when calling `ddcutil`
* Rework logging system
* Update required Python version in `setup.py`

* Add ability to report unsupported displays
* Fix `linux.XRandr` reporting unsupported wayland displays
* Merge 24 Patch CVE-2007-4559 from TrellixVulnTeam
* Remove deprecated `flatten_list` function
* Drop Python 3.6 support

* Log stages of `_debug.info`
* Fix `list_monitors_info` not fully respecting method kwarg (21)
* Fix windows fallback monitor info using wrong (non-unique) part of DeviceID

This is not a feature update but I bumped the minor version because that last change can potentially break some code.
If you referred to a monitor using a name like: `Acer {e6f07b5f-ee97-4a90-b076-33f57bf4eaa7}` then this release will break that as it changes how monitors are named when a model number is not available.
I suggest running `list_monitors` to see what the new names are.

* Remove WIP code snippet that was accidentally released