Currently, the GetPrefix() function is used to return the Alias property - and sometimes overridden to return something else. Rather than have a separate function the Alias property should instead be overridden in those circumstances where it is required. This will also improve code readability.
Issue was noticed while working on Improve creating multiple table joins
Refactored code regarding SQLSelectTableBase.GetPrefix. Closes #17.
Removed SQLSelectTableBase.GetPrefix() mustoverride function as there is no real association with a table. Basically an SQLSelectTableBase has an alias and a source (table / SELECT statement). The Alias is no longer overridden.