Merge branch 'master' of gitlab.com:gitlab-org/gitlab-ce

CHANGELOG

Gemfile

Gemfile.lock

app/assets/stylesheets/generic/forms.scss

app/assets/stylesheets/pages/notes.scss

app/helpers/blob_helper.rb

app/views/projects/_issuable_form.html.haml

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

lib/gitlab/markdown.rb

lib/gitlab/markdown/sanitization_filter.rb

lib/gitlab/markdown/task_list_filter.rb

spec/lib/gitlab/markdown/task_list_filter_spec.rb