GUAC-932: Initial cleanup of Angular code

An initial stab at cleaning up the Angular code, this change:

1. Removes legacy JavaScript files from the old GuacUI days
2. Migrates the history thumbnail code (recent connections) to guacHistory.js - a service, with a mild hack to get it working as-is before I continue rewriting the JS code dealing with connections
3. Stores auth information in cookies rather than local storage
4. Uses abstract auth service for retrieving tokens, rather than requiring ALL services to be aware of the auth token storage mechanism
5. Moves to a new "types/" directory convention for services defining objects, and migrates existing types accordingly.

:hocho:

I realize this change adds a TODONT, but I think it's probably better to get these changes reviewed now before I continue rewriting things, as *that* pull request would be unreasonably large.
Those 0's are the upper-left corner of the source rectangle and the upper-left corner of the destination rectangle respectively.

https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D.drawImage