[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] qweb debug mode restricted to --dev mode

Also moved the set_trace call in top of render_node() function so it
makes more sense.
[IMP] Make translation todo's readable when hovered
[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
[IMP] sale_crm: on opportunity form view, add a button linking to the
sales related to the current opportunity, using a stat button. Two fields are
introduced: opportunity_id on sale.order (automatically set when using the
make sale wizard), and sale_amount_total on the opportunity, function field
computing the total amount for the not canceled quotations related to the
opportunity.
[IMP] share: now restricted to the technical group, as this is a very
tricky feature. Also changed the order in the more menu.
[IMP] account, account_bank_statement_import: onboarding tips. Added 2 data files holding 2 tips for account, 1 for account_bank_statement_import.
[IMP] website: image controller can use xmlid
Merge pull request #2153 from odoo-dev/master-website-image-controller-chm

[IMP] website: image controller can use xmlid
[IMP] CRM: Improved meeting view for opprtunities, meetings are filtered for particular opprtunity. Improved schedule meeting task, event summary and attendees details will be automatically filled up using logged call details and meetings are linked with it's particular opportunity.