The history button doesn't seem to work in the JavaDoc
Index Search window in the Swing Browser.
Swing Browser is handled by openide/core. Reassigning.
SwingBrowser doesn't support history (we didn't need it when we used
icebrowser). It needs to be implemented.
Fixed button enabling in NB3.4 dev.
Reassinging to Marek. Maybe it would be better to close as WONTFIX if
there is no plan to implement this. Tim wanted to remove whole swing