[FIX] Adds .DS_Store file to ignore list
[NEW] Changes method names in Files utility to make it more verbose
[FIX] Adopted view helper to new file utility names
[NEW] Adds a new view helper for links

This is necessary because with the next commit external packages can deliver the content.
This view helper is not much more than the default link.action view helper but it set the package always to Scriptme.MarkdownContent. It's basically a convenience feature as you could do the same thing by setting the "package" property in the default link.action view helper
[NEW] Adds support for external packages

With this change set, external packages can provide all the content and structure for a website.
[FIX] Moved around the resources to match structural changes

This now matches the default structure of a Flow site package.