added getLineNumberAtCursor() method to ZString.

ZString.cpp

@@ -575,4 +575,13 @@ namespace coreutils {
       return temp;
    }
 
+   int ZString::getLineNumberAtCursor() {
+      int line = 1;
+      while(cursor != data) 
+	if(*cursor-- == '\n')
+	  ++line;
+      return line;      	   
+   }
+   
+   
 }

ZString.h

@@ -439,6 +439,13 @@ namespace coreutils {
 
       ZString removeTrailingZeros();
 
+      ///
+      /// Returns the number of line termination characters + 1 based upon
+      /// the cursor position.
+      ///
+
+      int getLineNumberAtCursor();
+      
     protected:
       char *data;
       char *cursor;