Columns: elements names informations are now kept in a memory arena of

adapted size in the header, and added a boolean in the header indicating
whether the values should be evaluated (typically character strings to
be evaluated in Python)

src/obiview.h

@@ -361,7 +361,10 @@ Obiview_p obi_open_view(OBIDMS_p dms, const char* view_name);
  * @param nb_elements_per_line The number of elements per line, if the column is created.
  * @param elements_names The names of the elements with ';' as separator (no terminal ';'),
  * 						 if the column is created; NULL or "" if the default names are to be used ("0\01\02\0...\0n").
+ * @param elt_names_formatted Whether the separator for the elements names is ';' (false), or '\0' (true, as formatted by format_elements_names()).
  * @param tuples A boolean indicating whether the column should contain indices referring to indexed tuples.
+ * @param to_eval A boolean indicating whether the column contains expressions that should be evaluated
+ *                (typically OBI_STR columns containing character strings to be evaluated by Python).
  * @param indexer_name The name of the indexer if there is one associated with the column, if the column is created.
  *                     If NULL or "", the indexer name is set as the column name.
  * @param associated_column_name The name of the associated column if there is one (otherwise NULL or ""), if the column is created.
@@ -384,7 +387,9 @@ int obi_view_add_column(Obiview_p    view,
 						index_t      nb_lines,
 						index_t      nb_elements_per_line,
 						char*        elements_names,
+						bool         elt_names_formatted,
 						bool         tuples,
+						bool         to_eval,
 						const char*  indexer_name,
 						const char*  associated_column_name,
 						obiversion_t associated_column_version,