Indicate when a toot is part of a chain with a "reply all" icon (#1869)

app/assets/javascripts/components/components/status_action_bar.jsx

@@ -98,7 +98,7 @@ const StatusActionBar = React.createClass({
 
     return (
       <div style={{ marginTop: '10px', overflow: 'hidden' }}>
-        <div style={{ float: 'left', marginRight: '18px'}}><IconButton title={intl.formatMessage(messages.reply)} icon='reply' onClick={this.handleReplyClick} /></div>
+        <div style={{ float: 'left', marginRight: '18px'}}><IconButton title={intl.formatMessage(messages.reply)} icon={status.get('in_reply_to_id', null) === null ? 'reply' : 'reply-all'} onClick={this.handleReplyClick} /></div>
         <div style={{ float: 'left', marginRight: '18px'}}><IconButton disabled={status.get('visibility') === 'private' || status.get('visibility') === 'direct'} active={status.get('reblogged')} title={intl.formatMessage(messages.reblog)} icon={reblogIcon} onClick={this.handleReblogClick} /></div>
         <div style={{ float: 'left', marginRight: '18px'}}><IconButton animate={true} active={status.get('favourited')} title={intl.formatMessage(messages.favourite)} icon='star' onClick={this.handleFavouriteClick} activeStyle={{ color: '#ca8f04' }} /></div>
 

app/assets/javascripts/components/features/status/components/action_bar.jsx

@@ -77,7 +77,7 @@ const ActionBar = React.createClass({
 
     return (
       <div className='detailed-status__action-bar'>
-        <div style={{ flex: '1 1 auto', textAlign: 'center' }}><IconButton title={intl.formatMessage(messages.reply)} icon='reply' onClick={this.handleReplyClick} /></div>
+        <div style={{ flex: '1 1 auto', textAlign: 'center' }}><IconButton title={intl.formatMessage(messages.reply)} icon={status.get('in_reply_to_id', null) === null ? 'reply' : 'reply-all'} onClick={this.handleReplyClick} /></div>
         <div style={{ flex: '1 1 auto', textAlign: 'center' }}><IconButton disabled={status.get('visibility') === 'direct' || status.get('visibility') === 'private'} active={status.get('reblogged')} title={intl.formatMessage(messages.reblog)} icon={reblogIcon} onClick={this.handleReblogClick} /></div>
         <div style={{ flex: '1 1 auto', textAlign: 'center' }}><IconButton animate={true} active={status.get('favourited')} title={intl.formatMessage(messages.favourite)} icon='star' onClick={this.handleFavouriteClick} activeStyle={{ color: '#ca8f04' }} /></div>
         <div style={{ flex: '1 1 auto', textAlign: 'center' }}><DropdownMenu size={18} icon='ellipsis-h' items={menu} direction="left" /></div>