scan_path(): Do not recurse into hidden directories by default

Paths that start with a period ('.') are considered hidden in the Unix world.
scan_path() should arguably not recurse into these directories by default.
This patch makes it so, and introduces the "scan-hidden-path" config variable
for overriding the new default and revert to the old behaviour (scanning _all_
directories, including hidden .directories).

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Lars Hjemli <larsh@prediktor.no>

cgit.h

@@ -207,6 +207,7 @@ struct cgit_config {
 	int noheader;
 	int renamelimit;
 	int remove_suffix;
+	int scan_hidden_path;
 	int section_from_path;
 	int snapshots;
 	int summary_branches;