Add Support for More Monitors per Output, and Vertical Layouts

[cdiddy1979]

I think the title says it all.  I like these configs, and it would be nice if deskhop supported it:

------------------------------------------            ------------------------------------------
|    A    |    A    |    B    |    B    |              |    A    |    A    |    A    |    A    | 
------------------------------------------             ------------------------------------------
|    A    |    A    |    B    |    B    |              |    B    |    B    |    B    |    B    | 
------------------------------------------             ------------------------------------------

This next one sort of works today, but the cursor jumps screens unexpectedly sometimes.  
This is not ergonomic, but its what fits on my desk right now:
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|    A    |    A    |    A    |    A    |     A    |    B    |    B    |    B    | 
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