Reviewed by Dave.

    Reviewed by Dave.

	<rdar://problem/3890961> selecting an item on the Apache bugzilla query page can be sped up 10% (HTMLFormCollection)
	<rdar://problem/3890958> JavaScript that toggles checkboxes can be improved 73% (HTMLCollection,HTMLFormCollection)

	This avoids the O(N^2) penalty for named item traversal for form collections.

	It also combines the item traversal logic for all non-form
	collection operations into a single traverseNextItem
	function. This avoids having 5 copies of the big switch statement
	for this.

	Also fixed a bug that prevented the last form element from being removed properly.

        * khtml/html/html_formimpl.cpp:
        (DOM::removeFromVector):
	* khtml/dom/html_misc.cpp:
        (HTMLCollection::namedItems):
        * khtml/dom/html_misc.h:
        * khtml/ecma/kjs_html.cpp:
        (KJS::HTMLCollection::getNamedItems):
        * khtml/html/html_miscimpl.cpp:
        (HTMLCollectionImpl::traverseNextItem):
        (HTMLCollectionImpl::calcLength):
        (HTMLCollectionImpl::length):
        (HTMLCollectionImpl::item):
        (HTMLCollectionImpl::nextItem):
        (HTMLCollectionImpl::checkForNameMatch):
        (HTMLCollectionImpl::namedItem):
        (HTMLCollectionImpl::namedItems):
        (HTMLCollectionImpl::nextNamedItem):
        (HTMLFormCollectionImpl::calcLength):
        (HTMLFormCollectionImpl::namedItem):
        (HTMLFormCollectionImpl::nextNamedItem):
        (HTMLFormCollectionImpl::namedItems):
        * khtml/html/html_miscimpl.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8066 268f45cc-cd09-0410-ab3c-d52691b4dbfc