Fixes: U4-5380 Booting.aspx security issue
#U4-5379 Fixed Due in version: 7.1.6

Some users have not set an email, don't strip out empty entries
#U4-5385 fixed Due in version: 7.1.6
#U4-4673 Fixed Due in version: 7.1.6
Fixes: U4-5388 YSOD after doctype rename & U4-5387 Deleting Properties in document types causes "Object reference not set to an instance of an object"
Fixes: U4-5384 Custom ApiController routes not working after upgrade to 7.1.5
Bump version number
Fixes duplicate key error (U4-5385)
Merge branch '7.1.6' into 7.2.0

Conflicts:
	build/UmbracoVersion.txt
	src/Umbraco.Core/Configuration/UmbracoVersion.cs
	src/Umbraco.Web.UI/Umbraco.Web.UI.csproj