Added a URL endpoint to force a page reload

I couldn't find a way to do this, so I just did it myself.  I am using this as part of the watch/build process and finding that sometimes livereload will reload the page while I'm waiting for something else to finish processing.  When that process is finished I wanted to force a page reload.  I couldn't find a way to do this by looking at the source, so I ended up adding an endpoint @ /reload that will force a reload on all of the waiters.

Even if there is a way to do this within the context of the running python livereload script, this would give the ability to do it outside of that context (scripts/applications running beside livereload).