PLT-4376 iOS and Android: Keep the keyboard open after sending a message (#4377)

* Force keyboard to retain focus on submitting post on mobile

* Fix lint error

* Allow keyboard to stay closed if the keyboard was closed earlier before submitting

* Increase delay time and add to comment

* Remove pass through props on suggestion box

webapp/components/suggestion/suggestion_box.jsx

@@ -227,5 +227,6 @@ SuggestionBox.propTypes = {
 
     // explicitly name any input event handlers we override and need to manually call
     onChange: React.PropTypes.func,
+    onBlur: React.PropTypes.func,
     onKeyDown: React.PropTypes.func
 };