[FIX] account_analytic_analysis: Recurring invoice lines price if pricelist does not match

If the price according to price list is False, use default sale price in the recurring invoice lines
[FIX] account_analytic_analysis: Only allow to select sale pricelist for contracts
[FIX] website_event_track: remove trailing comma in speakers name in event tracks
[FIX] website: on adding a slide to slider, new slide is last on save

Before, the new slide was set as first slide
Moreover, the indicators were not correct neither