Disable jQuery global AJAX handlers

jQuery allows to define global AJAX handlers which will get fired for every request made with `$.ajax` or such. See documentation on [jQuery API website](http://api.jquery.com/category/ajax/global-ajax-event-handlers/).

I am currently profiling an app that defines some behaviors for the `ajaxStart` & `ajaxStop` handlers. The 2 handlers are triggered when MiniProfiler fetches results. I do not really care about these behavior end would like MiniProfiler to not trigger them. jQuery offers a boolean called `global` which can be used as an option for `$.ajax` to disable the global handlers. This pull request sets `global` to `false` for the MiniProfiler call that fetches the results and this resolves the problem for me. I thought I'll share this as others might encounter the situation.

BTW, thank you for building this tool, it is so awesome & useful. If you guys are ever in SF, I'll owe you a beer or two :smile: :beers: