The `Text` struct is too large.

[rj00a]

cargo clippy often complains that std::mem::size_of::<Text>() is too large. There are a few things that should be done.

• Stop using Cow<'static, str> everywhere and just use String. We can reintroduce it later if it turns out to be important.
• Get rid of the Option<bool>s by manually implementing Serialize and Deserialize. Use a bitset with two bits per Option<bool>.

[dyc3]

I'd like to take a stab at this.