Delete a link to the now obsolete stable version.
Fix #58: Report file export does not work with the Pentaho plugin

A temporary workaround until there will be proper method to handle
converter registration.
Merge remote-tracking branch 'origin/master'
Merge branch 'master' of https://github.com/mysticfall/pivot4j
Major refactoring efforts on renderer API.

- Remove assumptions for a grid style UI.
- Separate the callback interface from the renderer API.
Update libraries to the latest version.
Fix wrongly escaped property name in expression error message.
Remove /etc from the folder selection tree.
Fix launcher shortcut links and messages.

- Currently, labels are hard coded as Pentaho doesn't translate 
them in launcher overlays.
Update the documentation to reflect API changes.
Remove a reference to the removed RenderStrategy interface.
Merge branch 'master' of https://github.com/mysticfall/pivot4j