Add support for config param summary-tags

This parameter can be used to specify max number of tags to show on
the summary page. If not specified, all tags are printed.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

shared.c

@@ -38,6 +38,7 @@ int cgit_cache_dynamic_ttl     =  5;
 int cgit_cache_static_ttl      = -1;
 int cgit_cache_max_create_time =  5;
 int cgit_summary_log           =  0;
+int cgit_summary_tags          =  0;
 int cgit_renamelimit           = -1;
 
 int cgit_max_msg_len = 60;
@@ -181,6 +182,8 @@ void cgit_global_config_cb(const char *name, const char *value)
 		cgit_max_commit_count = atoi(value);
 	else if (!strcmp(name, "summary-log"))
 		cgit_summary_log = atoi(value);
+	else if (!strcmp(name, "summary-tags"))
+		cgit_summary_tags = atoi(value);
 	else if (!strcmp(name, "agefile"))
 		cgit_agefile = xstrdup(value);
 	else if (!strcmp(name, "renamelimit"))