first attempt at creating a whitelist
added viewName to callbackId assignment in the callbackList to make the callbacks unique and allow better callback behaviour
ios: added filetype whitelist, load from relative /www folder, fixed loadRequest for non html files, added error handle for Create with bad src option
Merge branch 'v3.0' into feature/extWhitelist

Conflicts:
	ios/project/Plugins/WizViewManagerPlugin/WizViewManagerPlugin.m
	ios/project/Plugins/WizViewManagerPlugin/WizWebView.m
added extension whitelist and local relative file loading
updated readme with more information on loading source types
removed whitespace and load source from setLayout API
removed whitespace and load source from setLayout API
quick patch to allow for valid urls with no extension