Create DB: v_exp_mailchimp column names match Mailchimp

Using the same names simplifies the upload process
New Mailchimp update script

Updates Mailchimp list via API based on data from v_exp_mailchimp view
Mailchimp list name is defined as constant in core.php
New fields in Mailchimp

The following fields were added in Mailchimp in preparation for upload
process and to allow sending of campaigns for data validation by
subscribers

- erreurs
- chkpart
Move famille with kids not sharing data to calculated field

Before, this was considered as an error and reported as text in erreurs
table. This message was quite long and may not be an error, so it has
been moved to a dedicated flag field that can be used in a campaign to
display a custom message.
Setup script: display number of imported rows
Create v_exp_base as a base view for exports

Update v_exp_mailchimp to use the new view
New view v_exp_members to export members list
Add constants for grouping texts
Update: fix bug in update of groupings

Prior to this, the process would only update modified groupings,
resulting in unchanged items to be reset.
Update: fix updated records count
Create DB: add status table

This allows tracking of last import and upload dates
Import: set last imported date
Update: use printf to display processed row
Update: only process rows updated since last upload
Update: pre-increment counter so row display starts with 1