adding resize ability

fixes issue #2

.jslintrc

@@ -2,6 +2,7 @@
   "indent": 2,
   "node": true,
   "predef": {
-		"atom": true
+		"atom": true,
+    "document": true
 	}
 }

lib/MessagePanelView.js

@@ -1,6 +1,7 @@
 "use strict";
 
 var
+  $ = require('space-pen').$,
   View = require('space-pen').View,
   inherits = require('./utils').inherits;
 
@@ -22,6 +23,10 @@ MessagePanelView.content = function () {
     class: 'am-panel tool-panel panel-bottom native-key-bindings',
     tabindex: '-1'
   }, function () {
+    this.div({
+      class: 'panel-resize-handle',
+      style: 'position: absolute; top: 0; left: 0; right: 0; height: 10px; cursor: row-resize; z-index: 3'
+    });
     this.div({
       class: 'panel-heading'
     }, function () {
@@ -63,6 +68,11 @@ MessagePanelView.content = function () {
 MessagePanelView.prototype.attach = function () {
   if (this.panel === undefined) {
     this.panel = atom.workspace.addBottomPanel({item: this});
+
+    var that = this;
+    this.panel.item.on("mousedown", ".panel-resize-handle", function () {
+      that.resizeStarted();
+    });
   } else {
     this.panel.show();
   }
@@ -73,6 +83,7 @@ MessagePanelView.prototype.close = function () {
     this.panel[this.closeMethod].call(this.panel);
     if (this.closeMethod === 'destroy') {
       this.panel = undefined;
+      this.resizeStopped();
     }
   }
 };
@@ -140,4 +151,33 @@ MessagePanelView.prototype.add = function (view) {
   this.body.append(view);
 };
 
+MessagePanelView.prototype.resizeStarted = function () {
+  $(this).css({
+    WebkitUserSelect: 'none'
+  });
+
+  $(document).on('mousemove', {that: this}, this.resizePanel);
+  $(document).on('mouseup', {that: this}, this.resizeStopped);
+};
+
+MessagePanelView.prototype.resizeStopped = function (e) {
+  $(e.data.that).css({
+    WebkitUserSelect: ''
+  });
+
+  $(document).off('mousemove', this.resizePanel);
+  $(document).off('mouseup', this.resizeStopped);
+};
+
+MessagePanelView.prototype.resizePanel = function (e) {
+  var
+    panelBody = $(".panel-body", e.data.that),
+    panelHeadingHeight = $(".panel-heading", e.data.that).height(),
+    newHeight = $(document.body).height() - e.pageY - panelHeadingHeight - 30;
+
+  panelBody.css({
+    maxHeight: newHeight
+  });
+};
+
 module.exports = MessagePanelView;