new example plus minor convenience changes to examples

I've been trying to debug a touch problem with signaturePad and Internet Explorer 10 on Windows 8. I created a full-window example to facilitate testing long strokes.

Separately, you might want to mention in your documentation somewhere that the following CSS is highly-recommended for compatibility with IE10:

    canvas { -ms-touch-action: none; }

I got the idea from [MSDN](http://msdn.microsoft.com/en-au/library/ie/hh673557(v=vs.85).aspx) and it works wonders.