[FIX] data dir when home is not a directory

Use site data dir instead of user data dir when user's home is not a directory.
Like system users created with /dev/null as home.

Stricter than before.
[IMP] stock: allow float precision for quantity qty multiple

e.g. if orders with packages of 1/2 quantity
Merge pull request #1343 from vice/master

[FIX] data dir when home is not a directory
[IMP] [DATA] product: added default product.product data (Miscellaneous), consumable and available for the point of sale.
[UPG] web: upgraded font-axesome to version 4.2. New icons! Shiny! Lots of fun!
[IMP] sale, website_quote: expiration date is usefull even without using the website_quote module, therefore movign the field to the sale module. It has also be added to the email templates defined in sale and portal_sale, as well as in reports.
[IMP] crm, sale_crm: onboarding-related fixes
- lead name is now called Opportunity, clearer, added a placeholder on the form view;
- type (contact type) field is now dedicated to the group_delivery_invoice_address group.
It is set for technical groups only in base, then upgraded to the correct group in the
sale module that defines this group