when no input is given, jump to the most frequent location

This replicates a feature of the original autojump that I use a lot.

I'm a complete C# noob, so the implementation is probably sub-par, but it should not be difficult to fix.

Jump.Location/JumpLocationCommand.cs

@@ -77,7 +77,7 @@ protected override void ProcessRecord()
                 return;
             }
 
-            if (Query == null) return;
+            if (Query == null) { Query = new string[] { "" }; }
 
             // If last term is absolute path it's probably because of autocomplition
             // so and we can safely process it here.