Modified the "sgml" and "xml" targets to stop if the sub-makes fail in any subdirectory; don't continue with remaining subdirs.
Modified the "sgml" and "xml" targets to stop if the sub-makes fail in
any subdirectory; don't continue with remaining subdirs.

Added "api", "ext", "lib", "mac", "ref", and "tut" targets to only do
submakes in those directories.  This is just a lot easier to use than
to cd into the subdir and use make.rules directly.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator