Fixes: U4-4430 MySql primary key issues
Backports fixes for legacy encoding checks and to not do any db lookups for the new membership providers and also ensures the legacy membership provider doesn't do any db lookups on init.
Merge remote-tracking branch 'origin/6.2.0' into 7.1.0

Conflicts:
	src/Umbraco.Core/Configuration/GlobalSettings.cs
	src/Umbraco.Core/Persistence/Migrations/Initial/DatabaseSchemaResult.cs
	src/Umbraco.Tests/Umbraco.Tests.csproj
	src/Umbraco.Web/Security/Providers/UsersMembershipProvider.cs
	src/umbraco.providers/members/UmbracoMembershipProvider.cs
fixes typo
Merge remote-tracking branch 'origin/6.2.0' into 7.1.0

Conflicts:
	src/Umbraco.Tests/Migrations/AlterMigrationTests.cs
Initial implementation of a new package installation approach based on PR-297. Everything is left internal as we don't know when something like this can be introduced.

Idea is to be able to install a complete package using the PackagingService, so that we eventually can obsolete the old Packager/Installer-code.
Adding a note about the usage of the PackageInstallation class in the PackagingService
oops, fixes some logic with a closing bracket in the wrong place
Merge branch '6.2.0' of https://github.com/umbraco/Umbraco-CMS into 6.2.0
oops, fixes some logic with a closing bracket in the wrong place
Merge remote-tracking branch 'origin/6.2.0' into 7.1.0

Conflicts:
	src/Umbraco.Core/Persistence/Migrations/Upgrades/TargetVersionSixTwoZero/AdditionalIndexesAndKeys.cs
	src/Umbraco.Core/Services/PackagingService.cs
	src/Umbraco.Core/Umbraco.Core.csproj
Added another property to a migration to specify a minimum current version - needed for specifically targeting a migration 'from' a version.  Finally got mysql upgrading from 6.1 to 7.1 without issue, had to re-order a few things and ensure some migrations don't execute based on the 'from' version.
Merge branch '7.1.0' of https://github.com/umbraco/Umbraco-CMS into 7.1.0