Reviewed by Kevin.

    Reviewed by Kevin.

	<rdar://problem/4026787> text typed after a link (pasted or Mail Link to this Page) is part of the link, underlined and colored blue

	The concept of this change is every time you type at the very
	start or very end of a link (even if nested in further inner
	elements), the typed text goes outside the link instead of inside.

	* khtml/editing/htmlediting.cpp:
        (khtml::InsertTextCommand::prepareForTextInsertion): Check whether
	we are at the first visible position or last visible position of a
	special element. For now this only includes HTML A elements that
	are links (i.e. they have an href).
	(khtml::isSpecialElement): Helper function that identifies special
	elements (for now only links).
        (khtml::isFirstVisiblePositionInSpecialElement): Checks if a given DOM
	position is equivalent to the first visible position in some containing
	editable special element.
        (khtml::positionBeforeNode): Returns the DOM position immediately
	before a node.
        (khtml::positionBeforeContainingSpecialElement): Gives a DOM
	position immediately before the outermost editable containing
	special element where the passed-in position is equivalent to the
	first visible position.
        (khtml::maxRangeOffset): Helper to get the maximum allowed
	range/position offset for a node, does the right thing based on
	whether the node would use a character offset or child offset.
        (khtml::isLastVisiblePositionInSpecialElement): Similar to above,
	but for end of node instead of start.
        (khtml::positionAfterNode): Ditto.
        (khtml::positionAfterContainingSpecialElement): Ditto.

	Some layout tests changed - I looked over all the diffs and found
	that the only changes were "junk nodes" like empty spans and text
	nodes moving from one spot in the tree to another. These changes
	are all harmless and do not affect layout or future editing.

        * layout-tests/editing/inserting/typing-003-expected.txt:
        * layout-tests/editing/style/remove-underline-across-paragraph-expected.txt:
        * layout-tests/editing/style/remove-underline-across-paragraph-in-bold-expected.txt:
        * layout-tests/editing/style/remove-underline-after-paragraph-expected.txt:
        * layout-tests/editing/style/remove-underline-after-paragraph-in-bold-expected.txt:
        * layout-tests/editing/style/remove-underline-expected.txt:
        * layout-tests/editing/style/remove-underline-from-stylesheet-expected.txt:
        * layout-tests/editing/style/remove-underline-in-bold-expected.txt:
        * layout-tests/editing/style/typing-style-003-expected.txt:
        * layout-tests/editing/style/unbold-in-bold-expected.txt:
        * layout-tests/editing/style/underline-expected.txt:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8868 268f45cc-cd09-0410-ab3c-d52691b4dbfc