Fixes deep clone of User object
ensure properties reset on deep clone of ContentType (this is just a fail safe check)
Fixes user cloning issues with allowed sections
Fixes: U4-4849 Cannot change a users language/sections in the back office
Fixes merge
U4-4851 - Umbraco.Field legacy names
Merge remote-tracking branch 'origin/6.2.1' into 7.1.3

Conflicts:
	src/Umbraco.Tests/Models/ContentTests.cs
	src/Umbraco.Tests/Models/ContentTypeTests.cs