Revisions: move status tracking and Env::* to Text, ...

[dhardy]

• All fields of Environment are moved into Text
• Action is replaced with Status (mostly because I found the ordering of Action unintuitive)
• Status-tracking is moved from TextDisplay to Text
• Added Text::configure. It really only asserts that a valid FontId is used.
• wrap: bool is replaced with wrap_width: f32, independent of the horizontal bounds used for alignment.
• Better documentation of preparation status and usage.
• Remove Deref, DerefMut, AsRef and AsMut impls on Text
• fn TextApi::display replaced with unchecked_display and TextApiExt::display(&self) -> Result<&TextDisplay, NotReady>`
• Rename crate::fonts::fonts to crate::fonts::library

This should make Text easier to use and facilitate custom variants of Text.