Help: Window title updated incorrectly

[xTibor]

When opening a manual page the Help app sets the window title based on the currently selected tree view node, not the actual manual page path passed to the open_page function. This causes incorrect window titles when following hyperlinks in the document or navigating through the history.

[shannonbooth]

I think it would make sense if following a hyperlink in Help would update the tree view selection to that item.

[shannonbooth]

Also, following some of the hyperlinks in Help seems to lead to a blank page for me? e.g the mount(8) link in mount(2) - and vice versa

[xTibor]

The blank pages are caused by the /.. unveil bug:

serenity/Kernel/FileSystem/VirtualFileSystem.cpp

Lines 724 to 726 in 1d2986e

	// FIXME: Figure out a nicer way to do this.
	if (String(path).contains("/.."))
	return KResult(-EINVAL);

[shannonbooth]

Made #1260 as I forgot about that bug. Kinda makes me want to do some Kernel work, but me reckons I already do enough low level kernel/bootloader work at my day job. IAlways nice to write some higher level code every so often.