recognize startup parameters

Usage: winix [options]
  -c             : a path to the config file
  --config       : a path to the config file
  -h             : print usage information
  --help         : print usage information
  -?             : print usage information

While here:
- let it be possible to parse multiple configs,
- fix: some error messages were not printed at startup.

winixd/core/config.h

@@ -53,10 +53,6 @@ class Config
 {
 public:
 
-	// name of the config file
-	// this is the parameter passed to winix programm
-	std::wstring config_file;
-
 	// server mode
 	// you can assign any string to it such as "production" "dev"
 	// this value is not used by winix itself
@@ -857,7 +853,7 @@ public:
 
 
 	Config();
-	bool ReadConfig(bool errors_to_stdout_, bool stdout_is_closed = true);
+	bool ReadConfig(const std::wstring & config_file);
 
 	/*
 	 *
@@ -902,11 +898,10 @@ public:
 private:
 
 	pt::SpaceParser parser;
-	bool errors_to_stdout;
 	Log log;
 
-	void ShowError();
-	void AssignValues(bool stdout_is_closed);
+	void ShowError(const std::wstring & config_file);
+	void AssignValues();
 	void SetAdditionalVariables();
 	void CheckPasswd();