Differentiate between system and user modules

[cblake]

Also worth mentioning is that you can 
    
    
    import dirA/strutils as myStrut, std/strutils as stdStrut
    
    
    Run

and then use symbols from either in the same client module. (You could 
naturally not use "as" on one of them and let it default to "strutils"..I did 
both for symmetry.)