Robert Maynard authored Oct 30, 2020 and Brad King committed Nov 19, 2020

Make handling more consistent:

   "-S" -> invalid
   "-S/path/to/source" -> valid
   "-S /path/to/source" -> valid
   "-S=/path/to/source" -> now valid

   "-D" -> invalid
   "-DStr" -> valid
   "-D Str" -> valid
   "-D=Str" -> now valid

   "--log-level=" -> invalid
   "--log-level" -> invalid
   "--log-level=2" -> valid
   "--log-level 2" -> now valid