Fixes ie issues in Hacker0x01#141 by eliminating infinite loop.

This commit does 2 specific things:

It makes date_input.jsx properly state-less, reducing complexity.

It also upgrades datepicker.jsx to prevent repeated calls clearing the state if it has already been cleared. IE would trigger an onChange every time we set its value to null, causing the clearSelection to bubble up, set state, set the value, and repeat ad nauseam. This also upgrades datepicker.jsx to follow best practices of using setState callbacks to prevent subtle timing bugs.

Author: dcousineau

dist/react-datepicker.js

@@ -155,11 +155,13 @@ return /******/ (function(modules) { // webpackBootstrap
 	  },
 
 	  clearSelected: function clearSelected() {
-	    this.props.onChange(null);
+	    if (this.state.selected === null) return;
 
 	    this.setState({
 	      selected: null
-	    });
+	    }, (function () {
+	      this.props.onChange(null);
+	    }).bind(this));
 	  },
 
 	  onInputClick: function onInputClick() {
@@ -675,22 +677,12 @@ return /******/ (function(modules) { // webpackBootstrap
 	    };
 	  },
 
-	  getInitialState: function getInitialState() {
-	    return {
-	      value: this.safeDateFormat(this.props.date)
-	    };
-	  },
-
 	  componentDidMount: function componentDidMount() {
 	    this.toggleFocus(this.props.focus);
 	  },
 
 	  componentWillReceiveProps: function componentWillReceiveProps(newProps) {
 	    this.toggleFocus(newProps.focus);
-
-	    this.setState({
-	      value: this.safeDateFormat(newProps.date)
-	    });
 	  },
 
 	  toggleFocus: function toggleFocus(focus) {
@@ -702,15 +694,12 @@ return /******/ (function(modules) { // webpackBootstrap
 	  },
 
 	  handleChange: function handleChange(event) {
-	    var date = moment(event.target.value, this.props.dateFormat, true);
-
-	    this.setState({
-	      value: event.target.value
-	    });
+	    var value = event.target.value;
+	    var date = moment(value, this.props.dateFormat, true);
 
 	    if (date.isValid()) {
 	      this.props.setSelected(new DateUtil(date));
-	    } else if (event.target.value === "") {
+	    } else if (value === "") {
 	      this.props.clearSelected();
 	    }
 	  },
@@ -743,7 +732,7 @@ return /******/ (function(modules) { // webpackBootstrap
 	      ref: "input",
 	      type: "text",
 	      name: this.props.name,
-	      value: this.state.value,
+	      value: this.safeDateFormat(this.props.date),
 	      onClick: this.handleClick,
 	      onKeyDown: this.handleKeyDown,
 	      onFocus: this.props.onFocus,