Very small patch for visibility in NodeResource

[baszero]

important methods should be made protected instead of private so that inheritation becomes easy.

[baszero]

I found a workaround so I don't need get getNode() to be protected.

[baszero]

I reopened this pull request as I really think that making those two methods protected makes fully sense and is really required.

Use Case / Reason:

• Let's say you have static files, located at /static/**
• In your XSL files, you reference those static files like <img src="/static/1.jpg"/>
• Using the NodeResource in order to serve those files, the files must be physically stored under /static
• Now you want to hide the physical location, so you want to map /static to /internal-static, means: you still reference the static files via /static , but physically they are stored at /internal-static...
• The easiest way to achieve this is to overwrite the NodeResource method getRepoPath() where you do the URL to Yarep-Path translation.

Example of overridden method in subclassed NodeResource class:

    protected String getRepositoryPath() throws Exception {
        String pathPrefix = getResourceConfigProperty("path-prefix");
        String path = getPath();
        if (pathPrefix == null) {
            return path;
        }
        int index = path.indexOf(pathPrefix);
        if (index != 0) {
            throw new IllegalArgumentException("Path <"+path+"> should start with <"+pathPrefix+">!");
        }
        String repositoryPath = path.substring(index + pathPrefix.length());
        return repositoryPath;
    }

Today you can not reuse the NodeResource and just override the getRepositoryPath() method because it is private.

I think that both getNode() and getRepoPath() should be made protected.