Patch Set 4: I would prefer that you didn't submit this; No score

I wonder if this should be extended to some project-wide ignore cache. A resource listener could be added that listens for resource changes to a project's .gitignore files and updates it internal state. This should give much better performance.

Also you should not read ".gitignore" files using java.io.File but using the Eclipse resource API. This should also take a project's charset into account. It is actually possible to set a custom charset for ".gitignore" files in Eclipse.

The next step would be to extend the usage to various other places in EGit (eg. label decorations, commit dialogs, add action, etc.).