Fix MySql dictionary issue

Conflicts:
	src/umbraco.cms/businesslogic/language/Item.cs
Updating nuget targets files, like on v7. Also updates nuget author name.
Bump version to RC
Update readme and remove non-functioning backups from install.ps1
Updating minimum required versions of dependencies to be the same as v7.
Fixes the dictionary query syntax properly for all db's
Fixes: U4-4394 7.0.4: Inconsistency in member tree listings

Conflicts:
	src/Umbraco.Core/Persistence/Querying/BaseExpressionHelper.cs
	src/Umbraco.Core/Persistence/Repositories/Interfaces/IMemberRepository.cs
	src/Umbraco.Core/Persistence/Repositories/MemberRepository.cs
	src/Umbraco.Web/Trees/MemberTreeController.cs
Merge remote-tracking branch 'origin/6.2.0' into 7.1.0

Conflicts:
	build/Build.bat
	build/NuSpecs/UmbracoCms.Core.nuspec
	build/NuSpecs/build/net40/UmbracoCms.targets
	build/NuSpecs/build/net45/UmbracoCms.targets
	build/NuSpecs/build/net451/UmbracoCms.targets
	src/Umbraco.Core/Persistence/Querying/BaseExpressionHelper.cs
	src/Umbraco.Core/Persistence/Repositories/Interfaces/IMemberRepository.cs
	src/Umbraco.Core/Persistence/Repositories/MemberRepository.cs
Fixes the CDF nuget reference since we need the latest version and it is marked as visible now (this just undoes our old workaround)