Compose buttons bar redesign + generalize dropdown (#194)

* Generalize compose dropdown for re-use

* wip stuffs

* new tootbox look and removed old doodle button files

* use the house icon for ...

app/javascript/mastodon/features/compose/containers/doodle_button_container.js

@@ -1,15 +0,0 @@
-import { connect } from 'react-redux';
-import DoodleButton from '../components/doodle_button';
-import { openModal } from '../../../actions/modal';
-
-const mapStateToProps = state => ({
-  disabled: state.getIn(['compose', 'is_uploading']) || (state.getIn(['compose', 'media_attachments']).size > 3 || state.getIn(['compose', 'media_attachments']).some(m => m.get('type') === 'video')),
-});
-
-const mapDispatchToProps = dispatch => ({
-  onOpenCanvas () {
-    dispatch(openModal('DOODLE', { noEsc: true }));
-  },
-});
-
-export default connect(mapStateToProps, mapDispatchToProps)(DoodleButton);