Remove navigator.appVersion (deprecated)

[coudrak]

navigator.appVersion is deprecated, removed from the relevant web standards, is in the process of being dropped.

Chrome generates this issue: "In a future version of Chrome, the amount of information available in the User Agent string will be reduced. To fix this issue, replace the usage of navigator.userAgent, navigator.appVersion, and navigator.platform with feature detection, progressive enhancement, or migrate to navigator.userAgentData."

I rather suggest to drop the IE support, even MS doesn't support anymore IE.