CComponentsItem: move/rename doCenter()to base class CComponentsItem

So it's possible to use this method for all cc-items.
setCenterPos() comes now with parameter 'along_mode' (CC_ALONG_X, CC_ALONG_Y).
So it's possible to center in x or y direction. As default are
both directions predefined.


Origin commit data
------------------
Commit: 8a897103ac
Author: Thilo Graf <dbt@novatux.de>
Date: 2014-02-27 (Thu, 27 Feb 2014)

src/gui/buildinfo.cpp

@@ -3,7 +3,7 @@
 	Copyright (C) 2001 by Steffen Hehn 'McClean'
 
 	Copyright (C) 2013, M. Liebmann 'micha-bbg'
-	Copyright (C) 2013, Thilo Graf 'dbt'
+	Copyright (C) 2013-2014, Thilo Graf 'dbt'
 
 	License: GPL
 
@@ -43,7 +43,7 @@ CBuildInfo::CBuildInfo() : CComponentsWindow(0, 0, 700, 500, LOCALE_BUILDINFO_ME
 //init all var members
 void CBuildInfo::initVarBuildInfo()
 {
-	doCenter();
+	setCenterPos();
 
 	font = NULL;
 	setWindowHeaderButtons(CComponentsHeader::CC_BTN_MENU | CComponentsHeader::CC_BTN_EXIT);