typo

s/nonexiting/non-existing
Merge pull request #1945 from MadeleineHero/master

[FIX] typo
[IMP] web_tip: convert web_tip model to v8 api
[FIX] web_tip: grant write permission to users
[IMP] web_tip: add support for list views
[FIX] web_tip: consume can effectively use the api.multi decorator, to perform write in batch.
[IMP] website.snippet: convert media snippet into the new snippet api
[FIX] web: remove old datetimepicker and change by bootstrap datetimepicker
[FIX] web: update moment and datepicker library also add a controller to lazily load locale
[IMP] Replace gantt chart library with dhtmlxgantt 2.1.1