Patch for QueryParser to avoid throwing lots of exceptions that slows down the debugger

[franckspike]

Patch for QueryParser to avoid throwing lots of exceptions as part of main control flow. When called very often, it slowed down a lot the execution time when the visual studio debugger was attached. This patch enhance the performance of the QueryParser under a debugger.

[synhershko]

Thanks. We are not actively maintaining the 3.x branch as we put all our efforts in having a 4.x release soon. I'll be keeping this around for a reference.