ensures the mail usage is disposed.
Fixes: U4-4005 Member custom properties not saving from code, only from backend, wraps more of the getter functions in legacy member class with new member service methods, fixes paged result method when there are no results.
Merge remote-tracking branch 'origin/6.2.0' into 7.0.2

Conflicts:
	src/Umbraco.Core/Services/NotificationService.cs
Merge remote-tracking branch 'origin/6.2.0' into 7.0.2

Conflicts:
	src/Umbraco.Core/Persistence/Repositories/MemberRepository.cs
Fixes: U4-4039 @Umbraco.Field("writerName") etc. don't work any more
Merge branch '7.0.2' of https://github.com/umbraco/Umbraco-CMS into 7.0.2