remove at(index) reference function

remove chrUpr and chrLwr from PIString

libs/main/core/pistring.h

@@ -101,12 +101,6 @@ public:
 	 * Example: \snippet pistring.cpp PIString::char* */
 	operator const char*() {return data();}
 	
-	//! Return symbol at index "pos"
-	PIChar operator [](const int pos) const {return at(pos);}
-	
-	//! Return reference to symbol at index "pos"
-	PIChar & operator [](const int pos) {return at(pos);}
-
 	//! Compare operator
 	bool operator ==(const PIString & str) const;
 
@@ -790,9 +784,6 @@ inline PIString operator +(const char c, const PIString & f) {return PIChar(c) +
 //! \relatesalso PIString \brief Return concatenated string
 inline PIString operator +(const PIString & f, const char c) {return f + PIChar(c);}
 
-inline char chrUpr(char c);
-inline char chrLwr(char c);
-
 
 int versionCompare(const PIString & v0, const PIString & v1, int components = 6);