schema;res/app:dock:: add classic display mode(a.k.a. xp mode).

1. change new name for different modes.
2. add classic display mode.
3. do not set default mode css on html.
4. move img to different theme directory.
5. using css to control the hover/active/open style.
6. tray icons are hidden on startup, shown after dock is shown.
7. change XXXWarp to XXXWrap.
8. use flex-box to handle width of clientgroup, set -webkit-box-flex to 1.
9. set app_list's width to force flex-box work on classic mode.
10. set openindicator's width property to 100% to adapt the width automatically.
11. update po files, add "_Classic mode".

Change-Id: I65178337093217785a178ce053dfc58fbec0f20a