Implemented configurable HEAD shortlog on summary page.

This mirrors similiar functionality in gitweb. After clicking on
project on projectlist you will immediatelly see quick summary
of last N commits on HEAD.

[lh: changed from HEAD to cgit_query_head]

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

shared.c

@@ -34,6 +34,7 @@ int cgit_cache_repo_ttl        =  5;
 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_max_msg_len = 60;
 int cgit_max_repodesc_len = 60;
@@ -164,6 +165,8 @@ void cgit_global_config_cb(const char *name, const char *value)
 		cgit_max_repodesc_len = atoi(value);
 	else if (!strcmp(name, "max-commit-count"))
 		cgit_max_commit_count = atoi(value);
+	else if (!strcmp(name, "summary-log"))
+		cgit_summary_log = atoi(value);
 	else if (!strcmp(name, "agefile"))
 		cgit_agefile = xstrdup(value);
 	else if (!strcmp(name, "repo.group"))