This patch adds a specialized window type for notifications. They now
have a title bar on the right-hand side, with a close button.
This removes the need for the "Done" button in notifications, giving us
a bit more horizontal space overall.
Design based on a mock-up from @xTibor :^)
With this patch, it's now possible to pass a Gfx::ShareableBitmap in an
IPC message. As long as the message itself is synchronous, the bitmap
will be adopted by the receiving end, and disowned by the sender nicely
without any accounting effort like we've had to do in the past.
Use this in NotificationServer to allow sending arbitrary bitmaps as
icons instead of paths-to-icons.
When multiple notifications are open and one notification in the
beginning or in the middle is closed the location of the remaining
notification windows are updated so that there is no gap between them.
We currently use icon paths for this because I didn't want to deal with
implementing icon bitmap sharing right now. In the future it would be
better to post a bitmap somehow instead of a path.
Since the returned object is now owned by the callee object, we can
simply vend a ChildType&. This allows us to use "." instead of "->"
at the call site, which is quite nice. :^)
Don't stack notifications on top of each other, instead put them below
one another on the y axis.
This will obviously break if the screen fills with notifications, but
that's a FIXME for now. :^)
This patch adds NotificationServer, which runs as the "notify" user
and provides an IPC API for desktop notifications.
LibGUI gains the GUI::Notification class for showing notifications.
NotificationServer is spawned on demand and will unspawn after
dimissing all visible notifications. :^)
Finally, this also comes with a small /bin/notify utility.
