[FIX] res_partner: commercial partner sync

On child partner creation of a parent partner, the commercial_partner_id is not computed (and stored) in the create method.
Therefore, we should compute the commercial_partner_id before trying to sync his data
[FIX] survey: missing timezone conversions

As the survey hardcode lot's of views and reports in python, we do not beneficiate from automatic timezone conversions in the webclient.
Hopefully this is fixed in v8 after refactoring of the survey module. opw 608786
[ADD] res_partner: test case for fix rev 4a278809741d4e961ac13d3477a046d43b32cfa7
[MERGE] forward port of branch 7.0 up to e07bc5d
[Events] Solve Traceback in Event Registration Field.