This change adds SwiftLint to the project. For now, the rules are tweaked
to match the current state of the code base — but will over time be changed
back to their defaults in several cases.
Some smaller changes (mostly related to code style) were applied to the
project to remove all warnings.
Now that the decision not to support colors on Linux
has been made, we can replace the custom `Color` struct
with simple typealiases for `NSColor` and `UIColor`.
The same can’t be done for font, since we want to enable
loading of a font from a path, for SPM packages.
Now that we’re making Splash support iOS as well as
Mac + Linux, we need to create some nice abstractions
to make sure that we can share as much code as possible
between all platforms.
- Define Font.Loaded and Color.Renderable as platform-
specific typealiases for system fonts and colors.
- Don’t compile in non-Linux compatible code when building
for Linux.
- Make Font and Color handle all conversion themselves, so
that AttributedStringOutputFormat can be kept more clean.
