adapt base template for Bootstrap 3
Merge branch 'master' into 165-bootstrap3
bootstrap3-friendly buttons, forms, breadcrumbs, etc
make sure entity paths actually exist before checking file dupes

When entities are deleted the entity directory may stick around
if there is an addfiles.log or some other non-git file present.
proper bootstrap3 class for #celery-status alert box; url color

- Alert box had to have a contextual class (e.g. success, info,
  warning, danger) specified.
- We never know what alert is going there so just use "warning".
- CSS rule to make links same color as alert box.
Merge branch '165-bootstrap3'
fixed login form submit btn