C sources modified to add the handling of OBIDM columns with the type

OBI_INT, and the handling of multiple types in general

src/obidms.h

@@ -126,6 +126,23 @@ OBIDMS_p obi_open_dms(const char *dms_name);
 OBIDMS_p obi_dms(const char *dms_name);
 
 
+/**
+ * @brief Lists all the column directories in the OBIDMS, their data type and
+ * their latest version.
+ *
+ * @param dms a pointer as returned by obi_create_dms() or obi_open_dms().
+ *
+ * @return an integer value indicating the success of the operation.
+ *
+ * @retvalue 0 on success
+ * @retvalue -1 on failure and the `obi_errno` variable is set.
+ *
+ * @since July 2015
+ * @author Celine Mercier (celine.mercier@metabarcoding.org)
+ */
+int obi_list_columns(OBIDMS_p dms);
+
+
 /**
  * @brief Closes an opened OBITools Data Management instance (OBIDMS).
  *