Adds icons for all block ids. These are used in the client
application.

Implements javascript code for Overlay initialization.
Begins implementation of javascript Grid type.
Applies minor refactoring and code cleanup.
Amends TileSet type with some utility functions, needed by
the template processor.

Implements processing of all HTML, CSS and Javascript files.
This means executing templates and passing it in all the necessary
data. For this purpose, the Page type is created once and passed
into all of the templates.
Adds page.go file, holding the Page type.