Better handling and tracing of Index Errors between C and Cython

src/obierrno.h

@@ -118,6 +118,11 @@ extern int obi_errno;
 											 */
 #define OBI_ALIGN_ERROR				(29)    /** Error while aligning sequences
  	 	 	 	 	 	 	 	 	 	 	 */
+#define OBI_LINE_IDX_ERROR          (30)    /** Error setting or getting a value at a forbidden line index (greater than the line count of the view or the column)
+											 */
+#define OBI_ELT_IDX_ERROR           (31)    /** Error setting or getting a value at a non-existent element index or with a non-existent element name
+											 */
+
 /**@}*/
 
 #endif /* OBIERRNO_H_ */