Remove environment variables

[James Cipar]

Currently there are 2 locations where the cluster manager host and  
port are stored: in the config files, and in environment variables.   
This seems bad: there should be just 1 place for that information.   
This patch removes the need for the environment variables: the client  
code gets it's information from config files.  Now, the only  
environment variable that the code depends on is the PYTHONPATH.

-Jim