More work on "open window behind".

        * WebView.subproj/WebControllerPolicyDelegate.h: Add new OpenNewWindowBehind
	constants to the enums.

        * WebView.subproj/WebWindowOperationsDelegate.h: Add a behind: parameter to
	the openNewWindowWithURL method.

        * WebView.subproj/WebHTMLViewPrivate.m:
        (-[WebHTMLView _continueAfterClickPolicyForEvent:]): In the new
	WebClickPolicyOpenNewWindowBehind case, pass YES for behind.

        * Plugins.subproj/WebBaseNetscapePluginView.m:
        (-[WebBaseNetscapePluginView loadRequest:inTarget:withNotifyData:]):
        * WebCoreSupport.subproj/WebBridge.m:
        (-[WebBridge openNewWindowWithURL:referrer:frameName:]):
        * WebView.subproj/WebDefaultContextMenuDelegate.m:
        (-[WebDefaultContextMenuDelegate openNewWindowWithURL:referrer:]):
        * WebView.subproj/WebFrame.m:
        (-[WebFrame frameNamed:]):
	Pass NO for behind.

WebBrowser:

	More work on "open window behind".

        * BrowserWebController.m:
        (-[BrowserWebController openNewWindowWithURL:referrer:behind:]): Add new behind
	parameter to match change to window operations delegate in WebKit.
        (-[BrowserWebController clickPolicyForElement:button:modifierFlags:]): Use the
	WebClickPolicyOpenNewWindowBehind policy if the shift key and command key are down.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@2227 268f45cc-cd09-0410-ab3c-d52691b4dbfc