cubicweb-blog #711679 Generate & use readable URLs from blogentry title [in-progress]

A BlogEntry with title "this is a title" would generate a URL such as : /blogentry/this-is-a-title .

This is a specific request for the general rule ticket found here :

done in<not specified>
closed by<not specified>
patch[entity] use title as rest path (closes #711679) WIP (cf comment on ticket) [folded]