difftool.<tool>.path::
	Override the path for the given tool.  This is useful in case
	your tool is not in the PATH.

difftool.<tool>.cmd::
	Specify the command to invoke the specified diff tool.
	The specified command is evaluated in shell with the following
	variables available:  'LOCAL' is set to the name of the temporary
	file containing the contents of the diff pre-image and 'REMOTE'
	is set to the name of the temporary file containing the contents
	of the diff post-image.

difftool.prompt::
	Prompt before each invocation of the diff tool.