Miscellaneous Fixes and Improvements

This should finish everything for [v. 0.2](https://github.com/zodern/Silk/wiki/Roadmap)

Changes:
- fixed error from iframe url being src="{{url}}".
- running apps have a white bar above them
- when you click on an app that is behind another app, it is moved to the top instead of being minimized
- Windows can be closed and the iframe is removed
- Text editor warns of losing changes before opening another file
- The text editor has a yellow save button, and the bottom border of the toolbar becomes yellow when the file is changed
- Created a CLI app for silk.  Typing `silk` will start silk.  `-d` logs more information to the console, and `-r` makes silk available remotely
- Improved look of task bar, close and minimize buttons.  It is not possible to select text/images in Silk (you can select in apps).
- changed look of file explorer.  It currently is grid view.
- fixed error from channel being created early when opening file
-  Added a clock in the taskbar.