Do not add yaml_file to cassandra.yaml
Remove --yaml from updateconf
Allow for specification of subfields in nested yaml blocks
Do not coerce False or True to integers
Handle yaml entry not existing

The isinstance(x, dict) check throws a KeyError if the
new property is not already in cassandra.yaml.
Use psutil for pid tracking on windows
Update README for psutil dependency
Move psutil import in-line.

Now the dependency change will only be forced for users on Windows.
This will prevent Linux users from discovering a new dependency
has been added.
Remove yaml_merge test
If psutil not installed, gracefully fall back to old behavior
Merge pull request #177 from pcmanus/psutil

Use Psutil for pid tracking on windows
Merge branch 'master' into dse

Conflicts:
	ccmlib/common.py
Do not validate install_dir if -v passed
Add kwargs to check for old keyword args

This was needed for backwards compat. It was breaking dtests,
and probably would have broken many driver test suites.