Specify XSD for XML format


I opened this work item to document the changes I am making to the XML format while setting-up the XSD. Better than sending updates by email all the time.
The XSD is used for validating the XML before processing, and for providing intellisense in Visual Studio.
The intellisense comprises two sections: showing intellisense for the xml elements and attributes, and showing dropdowns with the data the user can provide, like Server, Database, Table and Column.
Because the order of input is important - we need to know which server was selected to be able to include the correct Database.xsd file.
For that reason I have had to change most of the settings from attributes to elements so that a sequence could be specified.
In order to limit complexity I set some restrictions:
We only have 1 database server selected at a time for both source and destination, so no cross-server operations in 1 script (one should be able to use 2 scripts if that were to be needed).
IgnoreAllTablesByDefault has been changed to ScriptRelatedTables