7229: rename some projects
7233: refactor
7238: RenderElement.ctor
7239: rename VisualTextRun
7243: focus on RenderElement.InvalidateGraphicArea
7247: remove InternalRect2
7249: refactor
7252: refactor
7261: refactor RootGraphic
Merge branch 'v_rootgfx' into v_dev
7267: ScrollBar sample

not finish!
7268
7270: drag sample
7271:
7272: move Demo to DemoList

use reflection technique for each demo
7273: update scrollbar sample
7281: scrollbar not complete
7283: UIScrollView sample

add UIScrollView sample,
UIPanel , Viewport Support
UIScrollRelation bind scrollbar and ScrollView
7284: update IParentLink
7285: VisualLayer.OwnerRenderElement