winix can drop privileges now (if started as the root)

added parameters to the config:
 user (string)
 group (string)
 additional_groups (bool)



git-svn-id: svn://ttmath.org/publicrep/winix/trunk@668 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/app.h

@@ -50,7 +50,8 @@ public:
 	bool Init();
 	void Start();
 	void Close();
-
+	bool DropPrivileges();
+	void LogUserGroups();
 
 
 	// configuration read from a config file
@@ -150,6 +151,12 @@ private:
 	bool IsCompressionAllowed(const std::string & source);
 	bool CanSendContent(Header header);
 
+	void LogUser(const char * msg, uid_t id);
+	void LogGroup(const char * msg, gid_t id, bool put_logend = true);
+	void LogUsers();
+	void LogEffectiveGroups(std::vector<gid_t> & tab);
+	void LogGroups();
+	bool DropPrivileges(const std::string & user, uid_t uid, gid_t gid, bool additional_groups);
 
 	// !! dodac do session managera?
 	time_t last_sessions_save;