2379: focus on image loading,ImageBinder
2380
2382: ImageContentManager

loading and manage image content
2383
2384: ImageCacheSystem
2388: block correction
2389: CssLineBox.PaintBackgroundAndBorder
2406: correcting CssBox Gen...
2409: fix CssLayout  ...
2415: correct CssBox Gen
Merge branch 'v1.7dev' into v1.7
2421: refactor CssLayoutEngine
 2422: refactor
2422: refactor
2425: refactor
2428: TextContentManager
2429: fix CssSpec

after change style
curSpec.VersionNumber++; //***
2431:CssBox's CalculationEpisode
2433: refactor
2434: refactor