Build result rendering framework

[kasper]

Build a framework for rendering AnalyzerResults to various formats (Swing, HTML, text, GWT, SWT etc.).

• Use a @RendererBean? annotation which can be used to group together renderers based on their format.
• Create a RendererDescriptor? similar to the other descriptors.
• Created a Renderer interface that renderer beans should implement.
• Fit in with existing descriptor providers.

[kasper]

This now works fine, as examplified by the TextDefaultRenderer? and TextCrosstabRenderer? (which has higher precedence if the result type is a CrosstabResult?).