Merge pull request #19 from numanSlm/branch_ushnish

Changed the name of the exception from a generic to a dedicated one

src/main/java/de/dennisguse/opentracks/share/ShareUtils.java

@@ -80,7 +80,7 @@ public static Intent newShareFileIntent(Context context, Track.Id... trackIds) {
     @Nullable
     public static Intent newShareFileIntent(Context context, Marker.Id... markerIds) {
         if (markerIds.length == 0) {
-            throw new RuntimeException("Need to share at least one marker.");
+            throw new ShareUtilsException("Need to share at least one marker.");
         }
 
         String mime = null;