Merge pull request #57 from amacgregor/master

Merged feature/code-pool-selection
Add generator for module XML file
Add listener to generate XML when classes are created
Prevent module generation when code generation is disabled
Hook up module generation in the container
Move responsibility for checking if module xml exists
Add pretty-xml dependancy
Generate config xml with blocks and models
Create etc directory if required
Bump pretty-xml version to fix whitespace errors
Remove unused argument
Add object wrapper for class_exists
Update XML after classes have been generated
Add source path to MageLoader
Refactor to support various config element types
Add support for resource models
Add controller support
Attach element generators in container
Support multiple code pools