V3.4.0 - Better caching dependency on folders and new CachingTimeOut property

This release has a revamped Markdown file caching and it includes a folder tree caching dependency to be able to invalidate caching when there are changes inside folders with nested subfolders. This is very useful for posts stored in a folder structure instead of all of them in the same folder or for special files such as sitemaps (although in that case, maybe disabling the cache for the sitemap is a good idea, since they are not frequently requested).

It adds a new property called CachingTimeOut that allows to specify the timeout in seconds to force the cache invalidation for any MIIS handled file (.md or .mdh). It can be set on the Front Matter of any file or in web.config to affect many files at once. If the timeout conflicts with the timeout set internally by any Front Matter source (for files that are going to be published in the future) the minimum of both values is used. This can be useful for especial Front Matter sources that get information from sources that you can't control hen they're refreshed. So, instead of setting the cache timeout value from the FM Source, it can be more flexibly established from the file itself using this property.

MIISFilesEnumeratorFMS.dll bumped to v1.2.0