[REM] website_blog: removed blog.post.history model and related stuff.
This is not necessary as we will soon have a way to store the various versions
of any website page, including the blog. Let's hope.
[IMP] project: reordered task kanban state selection.
[IMP] Project : Add Graph near Task and Issue,rename tab of form,focus + sign when empty kanban view,invisible remaining time when no managing time,don't show project name in bow if coming from a project,review default stage and change default group by