Support of smart internal links

[jacomago]

Often logbook entries have links to other log book entries.

Would be nice if there was a wikipedia style linking that

1. You can link to another entry by: [[#olog_id]]
2. You get a list of the titles of each link at the bottom of the entry. (references in a wikipedia article)
3. There is a way to see back links, i.e. see at the bottom of an entry all the entries that link to that olog id.