1.bugfix at HDFSRecovery.java, 2.rm BlackholeException.java, 3.use ParamsKey.java instead of AppConfigurationConstants.java
optimize retry-delete and retry-rename
Merge pull request #23 from cltlfcjin/master

1.bugfix at HDFSRecovery.java, 2.rm BlackholeException.java, 3.use ParamsKey.java instead of AppConfigurationConstants.java