[ADD] website: new blog demo snippets

(cherry picked from commit 6c6df546eb5a99d00d62fc6b497b4b861431423e)
(closes #2631)
[IMP] event: added auto confirmation of events, option available in configuration.

[IMP]Added non stored function field to visible/invisible seat_min field.

[IMP]Improved some code and removed unused chnages.