justinfrench/formtastic — pull request #947 by rainchen (2013-07-04 12:57:26+00:00)
Title: allow a proc to be given as label option

allow a proc to be given as label option, for example:
```
semantic_form_for(@new_post) do |builder|
builder.input(:title, :label => proc{ 'My label' })
end
```
see details: https://github.com/justinfrench/formtastic/issues/888