LILY-180: tags are not required per default
LILY-182: give reply_to default value of None so we don't get errors
Added DatePicker widget for Deal forms.
Removed some mwsadmin-era plugin references from Deal forms.
Fixed javascript error for Select2 initialization for empty tag-fields.
Fixed css full-(container)-width rendering for Select2 fields.
Restored previous-themed error pages until they're replaced.
Merge branch 'feature/theme-metronic' into develop
Restore mail_admins logging handler