Broke <FunctionSpecField/> into smaller parts.

src/components/fields/_DeleteStopButton.jsx

@@ -0,0 +1,25 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+
+import DocLabel from './DocLabel'
+import Button from '../Button'
+import DeleteIcon from 'react-icons/lib/md/delete'
+
+
+export default class DeleteStopButton extends React.Component {
+  static propTypes = {
+    onClick: PropTypes.func,
+  }
+
+  render() {
+    return <Button
+      className="maputnik-delete-stop"
+      onClick={this.props.onClick}
+    >
+      <DocLabel
+        label={<DeleteIcon />}
+        doc={"Remove zoom level stop."}
+      />
+    </Button>
+  }
+}