[FIX] sale: force default values for dropped fields

Those values were dropped at rev 3b636a5 but
need to be forced back to default so older
databases get properly updated when upgrading.
[FIX] mrp: force default values for dropped fields

Those values were dropped at rev 9b34358 but
need to be forced to empty so older databases
get fixed when upgrading
[FIX] website_event_track: force type from related to fix bug with convert_to_cache on picture
[FIX] website_blog: wait that document is ready before to check if we need to update menu for blog
[FIX] website_blog: change group restriction to load the JS editor
[FIX] website_blog: fix js error from 0a8aad990c86b18dfba5bb5dc964847fd97e7153