ui-stats: replace 'enable-stats' setting with 'max-stats'

The new 'max-stats' and 'repo.max-stats' settings makes it possible to
define the maximum statistics period, both globally and per repo. Hence,
it is now feasible to allow statistics on repositories with a high commit
frequency, like linux-2.6, by setting repo.max-stats to e.g. 'month'.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
diff --git a/cgit.h b/cgit.h
index 85045c4..f2cb671 100644
--- a/cgit.h
+++ b/cgit.h
@@ -61,7 +61,7 @@
 	int snapshots;
 	int enable_log_filecount;
 	int enable_log_linecount;
-	int enable_stats;
+	int max_stats;
 };
 
 struct cgit_repolist {
@@ -153,13 +153,13 @@
 	int enable_index_links;
 	int enable_log_filecount;
 	int enable_log_linecount;
-	int enable_stats;
 	int local_time;
 	int max_repo_count;
 	int max_commit_count;
 	int max_lock_attempts;
 	int max_msg_len;
 	int max_repodesc_len;
+	int max_stats;
 	int nocache;
 	int renamelimit;
 	int snapshots;