[FIX] load view from file shall not raise an exception

In --dev mode, when a view can't be loaded from the file in spite of
being referenced in field `arch_fs`, the current behavior is to raise
an exception. In most cases, developpers don't want the view to fail
so the behavior has been changed in favor of a logger warning and
a fallback to `arch_db`.
[ADD] QWeb2: add support for operation='attributes' in a t-extend

Same syntax as server's position='attributes' on view inheritance
[HACK] odoo design runbot team will install theme automatically
[ADD] push and start scripts
[ADD] Interface
Update designer interface
Added pull_changes in interface
Use interface for pushing changes
[IMP] Warn when pulling changes
[IMP] auto install/update particular theme if found
[IMP] Handle server update in interface
Minor changes
Added git-qdiff
[IMP] make discard changes safer
Added db manager in interface
[IMP] refactor menu entries
Clean *.pyc and empty folders when switching branches
[IMP] Start server and reset database == drop database
Error proof server update
Use git pull --rebase for server update