Merge branch 'remove-gray-bg'

CHANGELOG

app/assets/javascripts/activities.js.coffee

app/assets/javascripts/merge_request_tabs.js.coffee

app/assets/stylesheets/framework.scss

app/assets/stylesheets/framework/blocks.scss

app/assets/stylesheets/framework/buttons.scss

app/assets/stylesheets/framework/common.scss

app/assets/stylesheets/framework/files.scss

app/assets/stylesheets/framework/flash.scss

app/assets/stylesheets/framework/header.scss

app/assets/stylesheets/framework/layout.scss

app/assets/stylesheets/framework/lists.scss

app/assets/stylesheets/framework/markdown_area.scss

app/assets/stylesheets/framework/mixins.scss

app/assets/stylesheets/framework/mobile.scss

app/assets/stylesheets/framework/nav.scss

app/assets/stylesheets/framework/sidebar.scss

app/assets/stylesheets/framework/tables.scss

app/assets/stylesheets/framework/timeline.scss

app/assets/stylesheets/framework/tw_bootstrap.scss