The architecture here is really poor. Need to move file watching into a
dedicated location and probably have an spmc broadcast queue. other
modules besides rendering will care about config reloading in the
future.
This patch adds support for rendering italic fonts and bold fonts.
The `font` crate has a couple of new paradigms to support this: font
keys and glyph keys. `FontKey` is a lightweight (4 byte) identifier for
a font loaded out of the rasterizer. This replaces `FontDesc` for
rasterizing glyphs from a loaded font. `FontDesc` had the problem that
it contained two strings, and the glyph cache needs to store a copy of
the font key for every loaded glyph. `GlyphKey` is now passed to the
glyph rasterization method instead of a simple `char`. `GlyphKey`
contains information including font, size, and the character.
The rasterizer APIs do not define what happens when loading the same
font from a `FontDesc` more than once. It is assumed that the
application will track the resulting `FontKey` instead of asking the
font to be loaded multiple times.
Configuration may now be specified in either `$HOME/.alacritty.yml` or
`$HOME/.config/alacritty.yml`. See `alacritty.yml` in the repository
root for an example.
When a configuration file cannot be located, a default configuration is
used.
Joe Wilm