Allow Variant selection for Products without Options

Currently a bunch of code assumes that a product only has variants if it has options,
even though what really matters is whether there are variants.
This PR checks for the presence of variants instead of options.
Adding confirmation modal
Adding the modal translation
Behat tests
Small fix
Explicit error message
The button macro was not used...
Updating the behat tests
Add fallback to normal confirmation page when deleting item
Merge pull request #522 from stloyd/feature/confirmation-modal

Confirmation modal
Merge pull request #510 from Richtermeister/variants-over-options

Allow Variant selection for Products without Options
Fix issues found by SensioLabsInsight
Fix spec folder in OrderBundle
Fix for missing changes in some controllers