[FIX] Inject user context in all domain and context evaluation

Custom keys from user context may be used in action contexts (not just
e.g. searchview filters). For instance, have a custom key
context_salesteam (in the user model) and an action defining some
search default as a function of the salesteam.

In that case, the action's context evaluation (view.js:~275) will blow
up.

Ensure that does not happen.

Note: eval_contexts already injects user_context in the reduction of
contexts to evaluate. It should be possible to alter the reduction
function to avoid having to inject instance.session.user_context
through pyeval.context(), maybe by _.extend-ing ``result_context``
into ``evaluation_context`` at the *top* of the reduction function
rather than at its bottom?

bzr revid: xmo@openerp.com-20130128130640-ksyvxvx6rlc4820n

addons/web/static/src/js/pyeval.js

@@ -689,15 +689,14 @@ openerp.web.pyeval = function (instance) {
     };
 
     instance.web.pyeval.context = function () {
-        return {
-            uid: py.float.fromJSON(instance.session.uid),
+        return _.extend({
             datetime: datetime,
             context_today: context_today,
             time: time,
             relativedelta: relativedelta,
             current_date: py.PY_call(
                 time.strftime, [py.str.fromJSON('%Y-%m-%d')]),
-        };
+        }, instance.session.user_context);
     };
 
     /**