hdfs cleanup and compile test against CDH 4.4.
- hdfs cleanup; fix to NewDirectory to comply with definition in env.h
- fix compile error with env_test; static casts added
cleanup exception text
Merge pull request #154 from mrsqueeze/master

hdfs cleanup and compile test against CDH 4.4.
Print pthread_t in a more safe way
Merge pull request #156 from Chilledheart/print_pthread_info

Print pthread_t in a more safe way