Add a helper typedef to make it easier to query for the underlying character...

Add a helper typedef to make it easier to query for the underlying character type. Naming is conforming to stl

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3961 dfc29bdd-3216-0410-991c-e03cc46cb475

include/irrString.h

@@ -74,6 +74,8 @@ class string
 {
 public:
 
+	typedef T char_type;
+
 	//! Default constructor
 	string()
 	: array(0), allocated(1), used(1)