[webapi] Improve tests purpose description for File Writer API
Merge pull request #1105 from kangxu/kangxu/webapi/tct-filewriterapi-w3c-tests/improve

[webapi] Improve tests purpose description for File Writer API
[webapi]Modify suite.json to pack this suite into two apps

Impacted tests(approved):new 0,update 6,delete 0
Unit test platform:[Tizen IVI]
Unit test result summary:pass 6,fail 0,block 0
[webapi]Modify suite.json to pack this suite into two apps

Impacted tests(approved):new 0,update 2,delete 0
Unit test platform:[Tizen IVI]
Unit test result summary:pass 2,fail 0,block 0
Merge pull request #1096 from chenxix/chenxi/tizen/two-app-webstorage

[webapi]Modify suite.json to pack this suite into two apps
Merge pull request #1097 from chenxix/chenxi/tizen/two-app-extra

[webapi]Modify suite.json to pack this suite into two apps