Fixed the tinymce will remove link tag issue.
Merge branch '4.3'
Change: Site.Current -> page.Site.
Redesign the custom tabs for site setting and page editing page.
Able to extend the top toolbar button on the pages.
Fixed the compiling issue reported: http://forum.kooboo.com/yaf_postst3331_4-3-compilation-error.aspx
Build 4.3.8.218
Merge branch '4.3'

Conflicts:
	Kooboo.CMS/CMSAssemblyInfoGlobal.cs
	Kooboo.CMS/Publish/Default/Properties/AssemblyInfo.cs