[demo-express][TC-1429] Add privilege for Bookmark.
Update pack.py to support app postfix and seprate cordova and apk in suite.json
[xwalk-2152] Fix sandbox security

- Use colored div element instead of image element
- Add 'allow-same-origin' in allow-forms tests

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Android]
Unit test result summary: pass 1, fail 0, block 0
[xwalk-1326] Remove sample of CSS Style Attribute

- The feature for CSS Style Attribute (http://www.w3.org/TR/2013/REC-css-style-attr-20131107/) has been dropped, so remove this sample.
[sample-wrt][xwalk-2871] Update one case for demo-express

Impacted TCs num(approved): New 0, Update 1, Delete 0
Unit test Platform: Android
Android test result summary: Pass 1, Fail 0, Block 0
Merge pull request #25 from JianfengXu/xujf/1429

[demo-express][TC-1429] Add privilege for Bookmark.
Merge pull request #29 from haoxli/webapi/xwalk-2152

[xwalk-2152] Fix sandbox security
Merge pull request #30 from haoxli/webapi/xwalk-1326

[xwalk-1326] Remove sample of CSS Style Attribute
Merge pull request #31 from wanghongjuan/wrt/xwalk-2871

[sample-wrt][xwalk-2871] Update one case for demo-express
Merge pull request #26 from Honry/Honry/app-postfix

Update pack.py to support app postfix and seprate cordova and apk in sui...
 Edited README.md and modified snapshot image …

 Fixed some language in the README.md
 Added transparent background to snapshot image (and renamed .png)