Remove disableButtonIf[Any]EmptyField calls from forms

app/assets/javascripts/blob/edit_blob.js.coffee

app/assets/javascripts/blob/new_blob.js.coffee

app/assets/javascripts/labels.js.coffee

app/assets/javascripts/project_new.js.coffee

app/views/projects/blob/_remove.html.haml

app/views/projects/blob/edit.html.haml

app/views/projects/blob/new.html.haml

app/views/projects/branches/new.html.haml

app/views/projects/compare/_form.html.haml

app/views/projects/labels/_form.html.haml

app/views/projects/merge_requests/_form.html.haml

app/views/projects/merge_requests/_new_compare.html.haml

app/views/projects/merge_requests/_new_submit.html.haml

...ews/projects/merge_requests/widget/open/_accept.html.haml

app/views/projects/milestones/_form.html.haml

app/views/projects/network/show.html.haml

app/views/projects/new.html.haml

spec/javascripts/merge_request_spec.js.coffee