anchor.diff:  can be added to an existing group or scope using:
   
   -----------------------------------
  -add-highlighter <path> group <name>
  +add-highlighter <path>/<name> group 
   -----------------------------------
   
  -That group is then accessible using the *<path>/<name>* path
  +Other highlighters can then be added to that group
   
   ------------------------------------------------
   add-highlighter <path>/<name> <type> <params>...
   ------------------------------------------------
   
  -In order to specify which kinds of highlighters can be added to a given group, the *-passes*
  -flag set can be passed along with the group name. Possible values for this option can be one
  -or several (separated with a pipe sign) of *colorize*, *move* or *wrap* (default: *colorize*):
  +In order to specify which kinds of highlighters can be added to a
  +given group, the *-passes* flag set can be passed along with the group
  +name. Possible values for this option can be one or several (separated
  +with a pipe sign) of *colorize*, *move* or *wrap* (default: *colorize*):
   
   --------------------------------------------------------------
  -add-highlighter window group -passes colorize|move|wrap <name>
  +add-highlighter window/<name> group -passes colorize|move|wrap
   --------------------------------------------------------------
   
   == Regions highlighters
  
positive.code: 
  It can then be referenced in a window using the ref highlighter.
  
  ---------------------------------
  add-highlighter window ref <name>
  ---------------------------------
  
  The ref can reference any named highlighter in the shared scope.
  
negative.code: 
  Highlighters can be put in the shared scope in order to make them reusable.
  
  ---------------------------------
  add-highlighter shared/<name> ...
  ---------------------------------
  
  The common case would be to create a named shared group, or regions and then
  fill it with highlighters:
  
  ---------------------------------------
  add-highlighter shared/ group <name>
  