Fixes: U4-4592 U7.1 - You can trigger a lot  "Unsaved changes" bars
Hardcodes starterkit guid into the installer

This way we can change it remotely to another package instead of relying
on just getting the first guid in the collection of kits
Merge branch '7.1.0' of https://github.com/umbraco/Umbraco-CMS into 7.1.0
Updating user screen on the installer
Tiny tweak more