added b64 encode/decode to MString.

ZString.cpp

@@ -614,7 +614,11 @@ namespace coreutils {
       }
       return *this;
    }
-   
+
+   char ZString::getChar() {
+      return *cursor;
+   }
+      
    char ZString::nextChar() {
       char temp = 0;
       if(!eod())