This should enable to destinguish between IFrame, Reload and Navigation
motivated loads in order to call the appropriate hooks.
This change is motivated as loading the IFrame test page causes the
IFrame url to be added to the history and shows up as the current
browser location bar.
This patch adds a Web::Timer object that represents a single timer
registration made with window.setTimeout() or window.setInterval().
All live timers are owned by the DOM Window object.
The timers can be stopped via clearTimeout() or clearInterval().
Note that those API's are actually interchangeable, but we have to
support both.
* A PageView is a view onto a Page object.
* A Page always has a main Frame (root of Frame tree.)
* Page has a PageClient. PageView is a PageClient.
The goal here is to allow building another kind of view onto
a Page while keeping the rest of LibWeb intact.
LibWeb now creates a WindowObject which inherits from GlobalObject.
Allocation of the global object is moved out of the Interpreter ctor
to allow for specialized construction.
The existing Window interfaces are moved to WindowObject with their
implementation code in the new Window class.
