Code review existing GUI language parsing/AST/component generation code and architecture

[Keavon]

I'd love to sit down and talk through the codebase and find what should be redesigned or refactored before proceeding with building the DOM tree (#4). Having a second opinion on the usage of terminology throughout the code would be excellent as well. See this documentation for a primer on the GUI system. There's also a more detailed specification in a Google Doc that I need to convert to a Markdown file and add to the repo.

This code review pertains to the following files:

• gui_attributes.rs
• gui_node.rs
• layout_abstract_syntax.rs
• layout_abstract_types.rs
• layout_attribute_parser.rs
• layout_system.rs
• window_dom.rs
• window_events.rs

Entry point in application.rs:

let mut main_window_layout = LayoutSystem::new();
main_window_layout.add_window(("window", "main"));

[Keavon]

Shelved on account of switching to a web app frontend for the short term.