Revert "Merge branch 'improve-merge-requests' into 'master'

app/assets/javascripts/merge_request_widget.js.coffee

app/assets/stylesheets/pages/merge_requests.scss

app/helpers/merge_requests_helper.rb

app/models/merge_request.rb

app/models/merge_request_diff.rb

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

app/views/projects/merge_requests/show/_commits.html.haml

app/views/projects/merge_requests/show/_diffs.html.haml

app/views/projects/merge_requests/widget/_heading.html.haml

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

.../projects/merge_requests/widget/open/_conflicts.html.haml

doc/workflow/README.md

doc/workflow/merge_requests.md