Added docstrings.  Cleaned up code (broke up long lines, removed unused
variable references, pep8 formatted most of the code (one set of long lines
remains), and changed some variable and method names to conform to pylint
standards).

Fixes: 6530
Merge pull request #156 from ceph/teuthology-doc-hadoop-wusui

Added docstrings.  Cleaned up code (broke up long lines, removed unused