Squashed commit of the following:

    Added dom $ready event.

    Replace CES script tag with JavaScript script tag.

    Append script tags instead of using eval.

    Change link tag to script tag.

    Improved tests and added support for window selector.

    Added this keyword support.

    Added support and test for custom CES methods.

    Added support for custom CES method.

    Added todo.

    Added an instruction to prevent the default behavior.

    Support event and css selector selecting multiple elements.

    Fix line endings.
    Support event and CSS selectors than span over multiple lines.

    Fix bug about allowed characters in css/event selector attribute value.

    Added new test file.

    Refactoring.

    Added todo.

    Added todo.

    Improved error detection.

    Changed parsing method and adding parsing tests.