anchor.diff:    the full command or its description; if a command fails, the full command
     line will always be printed before the command's output.
   
  -`generator`:: if present, specifies that this rule is used to re-invoke
  -  the generator program.  Files built using `generator` rules are
  -  treated specially in two ways: firstly, they will not be rebuilt
  -  if the command line changes; and secondly, they are not cleaned
  -  by default.
  +`generator`:: if present, specifies that this rule is used to
  +  re-invoke the generator program.  Files built using `generator`
  +  rules are treated specially in two ways: firstly, they will not be
  +  rebuilt if the command line changes; and secondly, they are not
  +  cleaned by default.
   
   `restat`:: if present, causes Ninja to re-stat the command's outputs after
    execution of the command.  Each output whose modification time the command
  
positive.code: feature requires a Python installation.
  
  `graph`:: output a file in the syntax used by `graphviz`, a automatic
  graph layout tool.  Use it like: +ninja -t graph _target_ | dot -Tpng
  -ograph.png /dev/stdin+ .  In the Ninja source tree, `ninja graph.png`
  generates an image for Ninja itself.  If no target is given generate a
  graph for all root targets.
  
  `targets`:: output a list of targets either by rule or by depth.  If used
  like this +ninja -t targets rule _name_+ it prints the list of targets
  using the given rule to be built.  If no rule is given, it prints the source
  files (the leaves of the graph).  If used like this
  +ninja -t targets depth _digit_+ it
  prints the list of targets in a depth-first manner starting by the root
  targets (the ones with no outputs). Indentation is used to mark dependencies.
  If the depth is zero it prints all targets. If no arguments are provided
  +ninja -t targets depth 1+ is assumed. In this mode targets may be listed
  several times. If used like this +ninja -t targets all+ it
  prints all the targets available without indentation and it is way faster
  than the _depth_ mode.  It returns non-zero if an error occurs.
  
  `rules`:: output the list of all rules with their description if they have
  one.  It can be used to know which rule name to pass to
  
negative.code: Extra tools
  -----------
  
  The `-t` flag on the Ninja command line runs some tools that we have
  found useful during Ninja's development.  The current tools are:
  
  [horizontal]
  `query`:: dump the inputs and outputs of a given target.
  
  `browse`:: browse the dependency graph in a web browser.  Clicking a
  