Merged existing changes from 'develop'

build/webpack.base.conf.js

package.json

src/components/attachment/attachment.vue

src/components/media_upload/media_upload.js

src/components/post_status_form/post_status_form.js

src/components/post_status_form/post_status_form.vue

src/components/user_card_content/user_card_content.vue

src/lib/persisted_state.js

src/main.js

yarn.lock