Better handling of non-html over SSL

JIRA doesn't deal well with Microsoft products when being served over SSL when serving non-HTML resources. This is caused by a mismatch between how Microsoft treats Cache-Control headers and how JIRA sets them.

By default everything goes through the JiraCachingFilter and have no-cache and no-store added to the headers. Setting those means IE doesn't allow documents served over SSL to be stored to disk. This not only means you can't right-click-save them but if they are handled by external applications (Excel, Word, etc) you get error messages that are often strange and difficult to decipher.

So far we've had a piecemeal approach to fixing this: a customer reports a problem and we fix that one thing. First it was Word documents, then Excel, then RSS, then Workflows.

It would be better to consolidate our caching strategy into a central place, much as JiraCachingFilter works today, but with the knowledge of how to handle these other resources properly. Additionally some kind of Windows based selenium tests around all of these would be nice to help verify we don't ever regress, especially since none of our normal testing involves SSL.