add InitCommand and Context
- read putty ssh key from configuration
- refine..
- implement init command
- refine repo command
- add manifest Comparator
- check manifest files
- add test case for ManifestNameComparator
- ManifestComparator implement
- 增加 XML bean 校验
- 增加 Manifest 合并工具类
- 重构 Manifest 排序
- Fix Manifest NPE
- Add test case for Manifest utils
- remove junk
- optimize init command
- fix checkout/start command
- implement sync command
- save git config when clone repository