Investigate Quagga performance

[jgillard]

Will take some sample pics and run scripts to firstly find optimum settings, and secondly determine if the plugin is up to the job

[jgillard]

Code 128 scanning performance has been improved (apparently) https://github.com/serratus/quaggaJS#changelog

[LiyouZhou]

Nice, we should upgrade. Or should we just use a cdn pointing to the latest?