Bugfix: Fixes #128 Fixes issue where compressed/concatenated file breaks if angular is not present.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "showdown",
-  "version": "0.3.3",
+  "version": "0.3.4",
   "author": "John Fraser",
   "contributors": [
     "John Gruber",

src/ng-showdown.js

@@ -4,7 +4,7 @@
 
 
 //Check if AngularJs and Showdown is defined and only load ng-Showdown if both are present
-if (angular && Showdown) {
+if (typeof angular !== 'undefined'  && typeof Showdown !== 'undefined') {
 
     (function (module, Showdown) {