New feature: Bi-directional links

Typed relationships were one of the key features that distinguish Knowfox from its brethrem like Evernote. From its early days, it was possible to define such relationships between concepts. Also, through easy Markdown notation, I could define links to other concepts, e.g. [Awesome idea](/ 12345).

With this new update, links are now automatically extracted and turned into relationships of type link. This way, it is easy to go from the target back to the link source. Here is an example:

The link is extracted from the source text and identified as an internal link to another concept. On the target side, a backlink appears automatically.

As a smaller improvement, scheduled tasks are now linked with the journal entry for the target date: