[demo-express][XWALK-2560] Fix bug for mediaserver

- Fix bug for mediaserver
- Failure analysis: https://crosswalk-project.org/jira/browse/XWALK-1701

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Tizen IVI]
Unit test result summary: pass 0, fail 1, block 0
[demo-express] Reorder set nodes alphabetically.
Merge pull request #19 from JianfengXu/xujf/xml/set

LGTM 
[demo-express] Reorder set nodes alphabetically.
Merge pull request #17 from yunxliu/yunxliu/samples/mediaserver

[demo-express][XWALK-2560] Fix bug for mediaserver
[usecase-webapi] Improve NFC demo express

- Failure analysis: Tizen platform does't not support tag.writeNDEF

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Android]
Unit test result summary: pass 0, fail 1, block 0
Merge pull request #20 from zhuyongyong/yongzhu/usecase-webapi/nfc

[usecase-webapi][XWALK-2509] Improve NFC demo express
[xwalk-2722] Fix fullscreen scroll up/down

- Fix fullscreen block screen scroll up/down after return normal
- Fix similar name test will be marked as same result

Impacted tests(approved): new 0, update 1, delete 0
Unit test platform: [Android]
Unit test result summary: pass 1, fail 0, block 0
Merge pull request #21 from haoxli/haoxli/bug/xwalk-2722

[xwalk-2722] Fix fullscreen scroll up/down
Update version and README.md file
Merge pull request #22 from Honry/Honry/readme-preconfig-version

Update version and README.md file
Update README.md file
Merge pull request #23 from Honry/Honry/update-README.md

Update README.md file
update Readme
Merge pull request #24 from jennycao/update-readme-1

update Readme