Wrapping things up; we're now pretty much to spec!  &%O
 * Change PplmeMatchingPplProvider to actaully restrict the number of results
   to the configured maximum.
 * Remove the ability to configure the grid resolution as this doesn't really
   quite work properly yet (and a resolution of 1 seems to be performant
   enough).
 * Switch from PrototypeMatchingPplProvider to PplmeMatchingPplProvider.
 * Remove the ability to specify the maximum distance and add the ability to
   specify the maximum number of ppl from teh pplmed command line.
   And make the default 10.  D'oh!