apple-mobile-web-app-capable needs to be yes

[cheshrkat]

On iOS 9 and 10, manup.js was injecting the value of the manifest file, eg. <meta name="apple-mobile-web-app-capable" content="fullscreen">

However it must be 'yes', ie. <meta name="apple-mobile-web-app-capable" content="yes"> for iOS to respect it and other settings.

I had to remove manup.js to get fullscreen working on iOS as it overrides existing tags. So a generalised fix might be for manup to check for existing tags before injection; although that's slow. Otherwise there needs to be a catch to translate the iOS values from manifest values to yes.

[boyofgreen]

I think the latter will work (without much cost to perf). I'm planning do some clean up here soon, I'll make sure I fix this.