Do not refresh calendar on each event added

When displaying a lot of events, the calendar view spend a lot of time adding event one by one. This trigger a full update of the canvas at each addition.

assigned to @ced

added tryton type::performance + 1 deleted label

added 1 deleted label and removed 1 deleted label

review264841002 updated at https://codereview.tryton.org/264841002/#ps288611002

It requires rev 0e06a6be083e to not crash.

New changeset 3a05eb5d43e6 by Cédric Krier in branch 'default':
Use new event store when displaying calendar
https://hg.tryton.org/tryton/rev/3a05eb5d43e6

added 1 deleted label and removed 1 deleted label

closed

New changeset 2dc2870c558a by Cédric Krier in branch 'default':
Use new event store when displaying calendar
https://hg.tryton.org/tryton-env/rev/2dc2870c558a