Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- app/models/media_attachment.rb
  Upstream added audio attachment support
- app/serializers/initial_state_serializer.rb
  Upstream added audio attachment support and how mimetypes are returned
- app/serializers/rest/instance_serializer.rb
  Upstream added a few fields
- config/application.rb
  Upstream added a different paperclip transcoder

app/javascript/mastodon/features/compose/components/upload_button.js

@@ -7,9 +7,11 @@ import ImmutablePureComponent from 'react-immutable-pure-component';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 
 const messages = defineMessages({
-  upload: { id: 'upload_button.label', defaultMessage: 'Add media (JPEG, PNG, GIF, WebM, MP4, MOV)' },
+  upload: { id: 'upload_button.label', defaultMessage: 'Add media ({formats})' },
 });
 
+const SUPPORTED_FORMATS = 'JPEG, PNG, GIF, WebM, MP4, MOV, OGG, WAV, MP3, FLAC';
+
 const makeMapStateToProps = () => {
   const mapStateToProps = state => ({
     acceptContentTypes: state.getIn(['media_attachments', 'accept_content_types']),
@@ -60,9 +62,9 @@ class UploadButton extends ImmutablePureComponent {
 
     return (
       <div className='compose-form__upload-button'>
-        <IconButton icon='camera' title={intl.formatMessage(messages.upload)} disabled={disabled} onClick={this.handleClick} className='compose-form__upload-button-icon' size={18} inverted style={iconStyle} />
+        <IconButton icon='paperclip' title={intl.formatMessage(messages.upload, { formats: SUPPORTED_FORMATS })} disabled={disabled} onClick={this.handleClick} className='compose-form__upload-button-icon' size={18} inverted style={iconStyle} />
         <label>
-          <span style={{ display: 'none' }}>{intl.formatMessage(messages.upload)}</span>
+          <span style={{ display: 'none' }}>{intl.formatMessage(messages.upload, { formats: SUPPORTED_FORMATS })}</span>
           <input
             key={resetFileKey}
             ref={this.setRef}