Merge pull request #102 from v11985/data#40_wangfeng

Data#40 wangfeng ->yuanzhe
Data#40_yuanzhe:modify database structure for data sync
Data#yuanzhe:modify dao for insert history table
Data#40_yuanzhe:1.add revision field in contacts,documents,musics,pictures,videos tables.2.modify dao for those tables
Merge pull request #104 from huyuanzhe/Data#40_yuanzhe

Data#40 yuanzhe -> wangfeng
OK
Add function addFile,rmFile,chFile for other usage