Provides project based content manager implementation.

Project content source manager is capable of retrieving all contents inside a project.

Usage:

	// direct invocation
	IProject project = xxx;
	IContentSourceManager manager = new ProjectContentSourceManager(project);
	List<IContent> contents = manager.getRootContents(IContent.TYPE_S60_ALL);
	
	// or via the project design nature
	manager = S60DesignProjectNature.getUIDesignData(project);