Modernising the .NET 2 code with Resharpers help

Quite unreadable since it's mainly .NET 2 mode, so slowly linq'ifying
it.
Renamed ExportInformations to drop the s at the end.
Ran Resharper code cleanup on the whole MySqlBackup class (1400 lines
long!!!)
Export methods now pass the information about the export all the way
down, instead of keeping a local instance of it.