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: executed in order, may be used to rebuild those targets, assuming that all
  output files are out of date.
  
  `clean`:: remove built files.  If used like this +ninja -t clean+ it removes
  all the built files, except for those created by the generator.  If used
  like this +ninja -t clean -g+ it also removes built files created by the
  generator.  If used like this +ninja -t clean _targets..._+ it removes the
  given targets and recursively all files built for it.  If used like this
  +ninja -t clean -r _rules_+ it removes all files built using the given
  rules. The depfiles are not removed. Files created but not referenced in
  the graph are not removed. This tool takes in account the +-v+ and the +-n+
  options (note that +-n+ implies +-v+).  It returns non-zero if an error occurs.
  
  Ninja file reference
  --------------------
  
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
  