result:path missing filename could use better error report

[Tony Juricic]

I understood PATH to be onlu the directory path for result option.
-result:C:\Users\MyUserId\AppData\Local\Temp

Exceptions thrown are hard to interpret as missing file name. Perhaps a default file name can be appended? Like:
if(System.IO.Path.FileName(path)==null)
     System.Io.Path.Combine(path, "NUnitLiteResults.xml");

[Charlie Poole (charlie.poole)]

We should at least intercept the error and give a reasonable message. In addition, make it clearer in the help message.

[Charlie Poole (charlie.poole)]

After examination, I decided to leave the error message as is but to clarify the meaning of the parameter in the help.