Fix regression that broke simple play/pause usage

Fixes #1102 by restoring the check for a single paused sound when calling `play`.

src/howler.core.js

@@ -717,6 +717,24 @@
       } else if (typeof sprite === 'undefined') {
         // Use the default sound sprite (plays the full audio length).
         sprite = '__default';
+
+        // Check if there is a single paused sound that isn't ended. 
+        // If there is, play that sound. If not, continue as usual.  
+        if (!self._playLock) {
+          var num = 0;
+          for (var i=0; i<self._sounds.length; i++) {
+            if (self._sounds[i]._paused && !self._sounds[i]._ended) {
+              num++;
+              id = self._sounds[i]._id;
+            }
+          }
+
+          if (num === 1) {
+            sprite = null;
+          } else {
+            id = null;
+          }
+        }
       }
 
       // Get the selected node, or get one from the pool.