Wrap update check in function, reorganize

This puts this functionality into a function that can be dummied out now
and reorganizes the others.
awesometts.editor_button()

This one controls the editor button on the Add and browser windows, as
well as automatically disabling/enabling it.
Shortcuts and move some imports

Wrap the shortcut configuration setup and move some imports into
closures.
Browser menu component

Makes this loadable like the others.
Card layout button

This is now wrapped in a function, completing the set.