continued to work on new UI library

- implemented CgStatusBar widget which is a specific version of the CgIndicatorBar widget with predefined fields

- std::io::Screen is now an enum that makes switching between display modes more intuitive

- created a basic CgLineEdit implementation that allows for a user to type in a character and have it re-render that widget

- other more minor changes like fixes for existing apps to work with new features

src/lib.rs

@@ -8,6 +8,7 @@
 #![feature(abi_x86_interrupt)]
 #![feature(alloc_error_handler)]
 #![feature(async_fn_in_trait)]
+#![feature(async_closure)]
 #![feature(global_asm)]
 
 use core::panic::PanicInfo;