Provide a database upgrade script for the v1.8

Here:
* we add a session_key to the accounts table
* we add a 'initialize' column to the tel expense type (Ref #12)
* we update the models to fetch the new table structure
Add the initialize atribute in the config form

ref #12 : the initialize attribute tags an expense type for which a
default entry should be added in a new expense sheet.
Ref #12 Provide an expense tel form

We can now add tel expense lines through a form.
Here :
* we add buttons to popup this new form
* we provide a delete button for the tel lines
* we provide a form template
Provide default values to a model that will be added

Autonomie.addFormInitialize now handles a modelOptions that is used to
initialize the model bound to the current view.
This way, we can carry predefined attributes through the validation
process.
Ref #12 : allow to add tel types through the UI

Previously telephonic expenses were added automatically to the expense
sheet.
Now we provide a way to initialize them on demand. Consequently, the end
user should add/edit/delete expense types.
Here we provides the route and the view used for this purpose.
Ref #12 : only initialize tel types if configured so on

If the admin ask to auto-initialize a tel type, it's automatically added
to the expense sheet on initialization.
Merge branch 'gaston/#12'

Fix #12 : previously the telephonic expense lines were automatically added to
the expense sheet on initialization.  Now we provide a "initialize" attribute
to expense types that set if the expense should be added on initialization or
not. Consequently we also added a tel line add form to the end user.