Fix for issue #327 touch overriding mouse events.  Only allow touch on d...

...evices we know are touch only and not touch and keyboard.

I am new to setting things up differently for touch or mouse interactions but this would seem to fix https://github.com/aino/galleria/issues/327 since we would only set Galleria to touch mode for devices we knew were touch only.  Not quite a dynamic as basing touch on if touch is available but it should avoid conquering mouse input