[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?
[FIX] Use relative protocol in scripts url in order to avoid mixed content warnings in IE
[IMP] kanban: display number of folded records
[FIX] [IMP] kanban view: number of items in a column is now also displayed for folded columns. Indeed, using custom filters, it can be interesting to know whether there are items in the folded column. This branch also solves some CSS issues related to kanban view and re-indent some code.
[FIX] minor css fix
[CHG] allow deselecting a custom filter by clicking on it again in the drawer

as asked in project.task:4837:

> Cannot uncheck a custom filter by clicking on it (it's possible on
> classic filters)
[FIX] small issue with adding an attribute called 'id' to a backbone model

triggers backbone's thinking that the model is 'not new' and trying to sync it with a remote on e.g. removal
Launchpad automatic translations update.
Launchpad automatic translations update.
Launchpad automatic translations update.