[util] Add -n shorthand for --num-iterations

Meh.

util/options.cc

@@ -419,7 +419,7 @@ shape_options_t::add_options (option_parser_t *parser)
     {"cluster-level",	0, 0, G_OPTION_ARG_INT,		&this->cluster_level,		"Cluster merging level (default: 0)",	"0/1/2"},
     {"normalize-glyphs",0, 0, G_OPTION_ARG_NONE,	&this->normalize_glyphs,	"Rearrange glyph clusters in nominal order",	nullptr},
     {"verify",		0, 0, G_OPTION_ARG_NONE,	&this->verify,			"Perform sanity checks on shaping results",	nullptr},
-    {"num-iterations",	0, 0, G_OPTION_ARG_INT,		&this->num_iterations,		"Run shaper N times (default: 1)",	"N"},
+    {"num-iterations", 'n', 0, G_OPTION_ARG_INT,		&this->num_iterations,		"Run shaper N times (default: 1)",	"N"},
     {nullptr}
   };
   parser->add_group (entries,