Bcfg2 Client Code Refactoring

This branch is for work in decomposing the platform-specific client modules into service/packaging system-specific modules; the platform-specific modules will then just import the service/packaging system-specific modules they require (e.g. Redhat.py would import rpm.py and chkconfig.py, all the platforms will import encap.py, etc.)

A mailing list thread with more discussion of this is here:

• ​http://www-unix.mcs.anl.gov/web-mail-archive/lists/bcfg-dev/2006/07/msg00084.html

Desai's 4-Step Plan

1. create a module Bcfg2.Client.Tool.BaseTool that defines an API for all tools (things like Bcfg2.Client.Tool.RPM and Bcfg2.Client.Tool.SMF, etc)
2. build a set of error types that can be raised during tool instantiation and operation
3. modify the base client Toolset code to figure out what methods to call for entry verification, installation and removal.
4. is things like schema updates and metadata code updates

Desai might try to hack up a baseline for the BaseTool class soon.