Merge branch 'feature/theming2' into 'develop'

package.json

src/App.js

src/App.scss

src/_variables.scss

src/components/chat_panel/chat_panel.vue

src/components/color_input/color_input.vue

src/components/contrast_ratio/contrast_ratio.vue

src/components/delete_button/delete_button.vue

src/components/export_import/export_import.vue

src/components/font_control/font_control.js

src/components/font_control/font_control.vue

src/components/notification/notification.js

src/components/notification/notification.vue

src/components/notifications/notifications.scss

src/components/notifications/notifications.vue

src/components/opacity_input/opacity_input.vue

src/components/post_status_form/post_status_form.vue

src/components/range_input/range_input.vue

src/components/settings/settings.vue

src/components/shadow_control/shadow_control.js